Medical mask

Abstract

A device for delivering a gas to a user. The device includes a patient interface configured to surround a user's mouth and nose. The device also includes an outer chamber configured to receive gas from an external supply, where the outer chamber is secured to a patient-facing side of the patient interface, and includes one or more vent holes, where the one or more vent holes are configured to close when the device is secured to a user. The apparatus further includes a reservoir in fluid communication with the outer chamber; a connector configured to receive a gas flow from the outer chamber, the connector including one or more openings to allow gas exchange between the connector and the reservoir; an interior chamber in fluid communication with an airway of a user; one or more suction valves configured to allow gas to flow from the reservoir into the interior chamber when the gas pressure in the reservoir is higher than the gas pressure in the interior chamber; and an exhalation valve configured to allow gas to flow out of the device when gas pressure in the interior chamber exceeds ambient pressure.

Description

Technical Field

[0001] This specification relates to a device for delivering gas to a user, and more particularly to a medical mask with a gas connector. Background Art

[0002] There are many devices in the prior art for delivering gas to a patient that do not require the application of positive pressure to the patient's airway. These devices can be divided into closed devices that have no direct connection to the surrounding atmosphere and semi-open devices that have direct connection to the surrounding atmosphere. Examples of closed devices include a mouthpiece connected to a closed breathing system of sufficient capacity, or a mouthpiece used with a demand valve connected to a pressurized gas source, or a mouthpiece that completely replaces the patient's surroundings with the gas to be inhaled (for example, using a mask). The successful use of a mouthpiece requires good fit by the user; the mask requires high gas flow to maintain accurate administration, which increases cost.

[0003] Currently, semi-open devices used to deliver supplemental oxygen to patients work by increasing the amount of oxygen available to the patient above that typically found in atmospheric air. Any shortfall in the total volume of gas delivered compared to the volume of gas inhaled by the user is supplemented by the surrounding atmosphere (e.g., through vent holes between the mask and the surrounding atmosphere). Consequently, the amount of oxygen inhaled by the patient will mix with the atmosphere to varying degrees, with both device factors (e.g., leak area, device volume, ventilation resistance, oxygen flow rate) and patient factors (e.g., inspiratory flow rate, expiratory pause time) influencing the degree of dilution of the fresh gas flow entering the device. For example, when administering pure (100%) oxygen using a current industry-standard high-concentration, non-rebreathing oxygen mask, the actual inhaled oxygen concentration may be in the range of 60% to 80%. In practice, these values ​​vary considerably.

[0004] There is a need for a more efficient device for delivering medical gases to patients that provides an accurate concentration of the supplied gas. Summary of the Invention

[0005] This specification describes a device for delivering gas to a user. The device includes a patient interface configured to surround the user's mouth and nose. The device also includes an outer chamber configured to receive gas from an external supply, wherein the outer chamber is secured to a patient-facing side of the patient interface and includes one or more exhaust holes, wherein the one or more exhaust holes are configured to close when the device is secured to the user.

[0006] The device also includes: a reservoir in fluid communication with the outer chamber; a connector configured to receive a flow of gas from the outer chamber, the connector including one or more openings to allow gas exchange between the connector and the reservoir; an inner chamber in fluid communication with the user's airway; one or more inhalation valves configured to allow gas to flow from the reservoir into the inner chamber when the gas pressure in the reservoir is higher than the gas pressure in the inner chamber; and an exhalation valve configured to allow gas to flow out of the device when the gas pressure in the inner chamber exceeds the ambient pressure.

[0007] In one embodiment, the device is configured such that the outer wall of the outer chamber is continuously attached to the patient interface, and the inner wall of the outer chamber is attached to the patient interface at intervals to form one or more vents. The one or more vents can be configured to open when the device is not secured to the user.

[0008] The device may further include an anti-asphyxia valve connected to the connector, the anti-asphyxia valve being configured to remain closed when the gas pressure in the connector is equal to or exceeds the ambient pressure. The anti-asphyxia valve may be configured to open when the gas pressure in the connector is lower than the ambient pressure.

[0009] In some embodiments, the volume of the outer chamber is variable, and the outer chamber is configured to expand when receiving gas from an external supply while the one or more vents are closed.

[0010] The reservoir can be configured to store gas received from the connector when one or more inhalation valves are closed. In some embodiments, one or more inhalation valves are configured to open during an expiratory pause. In some embodiments, one or more inhalation valves are configured to open when a user inhales. In some embodiments, an exhalation valve is configured to open when a user exhales.

[0011] In some embodiments, the patient interface is deformable and / or resilient. For example, the patient interface can include memory foam.

[0012] Additionally, the device may further comprise one or more straps configured to secure the device in place during use. The one or more straps may be quick release straps.

[0013] The device may further comprise a medical gas connector for connection to an external gas supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 An apparatus according to the invention is shown;

[0015] Figure 2 shows a patient interface according to the present invention;

[0016] Figure 3 A clip for a strap according to an embodiment of the present invention is shown;

[0017] Figure 4 shows the arrangement of the straps according to an embodiment of the present invention;

[0018] Figure 5 An apparatus according to the invention is shown;

[0019] Figure 6 shows a front view of a patient interface according to the present invention;

[0020] Figure 7 Shown are a connector and an anti-asphyxia valve according to the present invention;

[0021] Figure 8 One or more inhalation valves and exhalation valves according to the present invention are shown;

[0022] Figure 9 A flow chart describing a user's breathing pattern is shown;

[0023] Figure 10a and Figure 10b Results of experiments using current industry standard high concentration non-rebreathing oxygen masks and a device according to the present invention are shown.

[0024] Figure 11 Shown Figure 1 Another view of the device shown. DETAILED DESCRIPTION

[0025] Figure 1 A schematic cross section of a device 100 for delivering gas to a user according to the present invention is shown. The device 100 is designed to deliver gas to a spontaneously breathing person without applying positive pressure to the airway during inspiration.

[0026] The device 100 includes a patient interface 101 that is configured to surround the mouth and nose of a user. The patient interface 101 can be deformable so that when secured to the user, the patient interface is shaped to conform to the contours of the user's face. Additionally or alternatively, the patient interface 101 can be resilient so that when removed from the user, it can return to its original shape. For example, the patient interface 101 can include memory foam, such as polyurethane memory foam. Other suitable materials are known to those skilled in the art.

[0027] Figure 2An example construction of a patient interface 101 is shown. The patient interface 101 includes a foam layer 201. The patient interface 101 also includes a fabric layer 202 covering three surfaces of the patient interface, the fabric layer 202 being configured to hold the foam layer 201 in position against the user's face. In the example construction, the fabric layer is applied to the patient-facing side of the patient interface 101, the outwardly facing side of the patient interface 101, the outer edge of the patient interface 101, such that the foam layer 201 is exposed at the inner edge of the patient interface. Non-woven polypropylene fabric is an example of a suitable fabric, although any other suitable material may be used.

[0028] During use, the device 100 is secured to the user. For example, the device 100 may include one or more straps (see Figure 4 ), which is configured to secure the device 100 in place during use. Figure 2 As shown, one or more straps may be attached to the patient interface 101 via one or more clips 203 . Figure 3 A closer view of an example clip 203 is shown in . One or more straps can be quick release straps configured to allow the device 100 to be quickly removed from the user, such as in an emergency. For example, the clip 203 can be connected to the buckle 301 to allow for quick release of an adjacent strap.

[0029] Figure 4 , an example is shown without the strap 400. The strap is designed to wrap around the back of the user's head to ensure a secure fit. The strap may include a lower strap 402, an upper strap 404, and a top strap 406. The top strap 406 may also include a tube strap 408 configured to hold an airway extending along the length of the top strap 406 when the device 100 is in use. Other methods may also be used to secure the device 100 in place during use.

[0030] Return to Figure 1 The device 100 further includes an outer chamber 102 , an inner chamber 103 , and a reservoir 104 . Figure 5 1 and 5. The arrangement of these chambers within the device 100 is also shown. The device includes an outer bag 501 and an inner bag 502. The outer bag 501 is connected to the inner bag 502 at locations 503a and 503b. Note that this connection 503 extends around the entire perimeter of the device 100 to form the outer chamber 102 and the reservoir 104. In particular, the inner chamber 103 is formed by the interior of the inner bag 502. The outer chamber 102 is formed between the patient interface 101 and the connection at 503, such that the outer wall of the outer chamber 102 is formed by the outer bag 501 and the inner wall of the outer chamber 102 is formed by the inner bag 502 (the outer surface). The reservoir 104 is formed on the other side of the connection at 503.

[0031] The device also includes one or more exhaust holes 105, such as Figure 1 shown. Figure 6 A front view of the patient interface 101 is shown. The outer bag 501 is continuously attached to the patient-facing side of the patient interface 101. The inner bag 502 is attached to the patient-facing side of the patient interface 101 at intervals to form one or more vents 105. The intervals can be evenly spaced so that each of the one or more vents has the same length. Alternatively, the intervals can be unevenly distributed. The length of each vent can be between 10 mm and 20 mm.

[0032] The one or more vents 105 are configured to be open when the device 100 is not secured to a user, such as Figure 6 As shown. When the device 100 is secured to the user, the patient interface 101 is shaped to the contours of the user's face as described above, closing one or more vents 105 to prevent gas from escaping from the outer chamber through the vents. In other words, the outer chamber 102 is formed and sealed by correctly applying the device 100 to the user. In this way, the fit of the patient interface 101 to the user can be tested. If gas leaks from the vents, the patient interface is not firmly formed to the user to form an airtight seal. This results in a loss of gas supply to the outside atmosphere. Such a leak can be detected by the user themselves, for example by sensing the flow of gas on the face, or by a medical professional observing that the outer chamber 102 is not expanding. The fit of the patient interface 101 can then be adjusted accordingly.

[0033] When properly applied to the user, device 100 creates a sealed environment with no atmospheric inflow. Therefore, the supplied gas is not diluted by the atmosphere as it passes through device 100. The user inhales only the gas supplied to the device from an external supply. Consequently, device 100 provides precise medical gas administration, with no variation in the concentration of administered gas between or within each breath. All ventilated areas of the lungs are exposed to the same concentration of gas without applying positive pressure to the airways or chest cavity. This simulates normal physiological conditions, where the lungs are in equilibrium with the atmosphere but metabolically consume oxygen and produce carbon dioxide.

[0034] Furthermore, when in use, the only gas flowing through device 100 is the supplied medical gas. Any air present in device 100 is swept away by the flow of supplied gas. If any micro-leakage exists in the device, some of the supplied gas flow will escape from device 100. However, as long as a sufficient volume and flow of supplied gas is maintained within and through device 100 to meet the user's needs, this "leakage flow" prevents the ambient atmosphere from entering device 100. This is clearly evident from the expansion of outer chamber 102 and the expansion / contraction of reservoir 104, so that the concentration of gas inhaled by the user remains constant.

[0035] The volume of the outer chamber 102 can be variable. For example, the outer bag 501 can include a flexible material. In one embodiment, the outer bag 501 and / or the inner bag 502 are formed from polyethylene or polypropylene.

[0036] With one or more vents 105 closed, the outer chamber 102 can be configured to visibly expand when receiving gas from an external supply. This allows for testing the fit of the patient interface 101 to the user, as any leaks will prevent the outer chamber from fully expanding. The expansion of the outer chamber 102 also allows anyone assisting the user and the user themselves to immediately and clearly see that the device 101 is properly fitting to the user.

[0037] Return to Figure 1 , gas enters the outer chamber 102 through an external supply. For example, the device 100 can include a medical gas connector 106, wherein the medical gas connector 106 is connected to the outer chamber 102. The other end of the medical gas connector 106 is connected to the external gas supply, such as through a tube. The medical gas connector 106 can be a standard connector, such as a 6 mm oxygen rod.

[0038] Gas can be supplied to the user's airway at a pressure consistent with the user's natural breathing pattern. For example, during normal operation, gas can be supplied to the medical gas connector 106, and therefore to the user's airway, at a pressure that does not exceed ambient pressure. In other words, no positive pressure is applied to the user's airway, and the user is able to breathe autonomously according to their natural breathing pattern.

[0039] The supplied gas can include any gas to be administered to the user, such as a therapeutic gas. For example, the gas can be pure oxygen, or a mixture of oxygen and another gas. Examples include nitric oxide (nitrogen and oxygen), helium oxide (helium and oxygen), argon oxide (argon and oxygen), and nitrous oxide (nitrous oxide and oxygen). In some embodiments, the supplied gas can be combined with the output of a vibrating mesh nebulizer to achieve delivery of an inhaled medication.

[0040] Device 100 enables precise administration of a known concentration of a medical gas mixture based on clinical needs. Because the inhaled gas mixture is precisely administered, the supplied gas can be titrated to the optimal clinical effect based on the latest medical research. This facilitates improved patient assessment, improved low-dependency respiratory support, and the ability to rescue patients to a clinical area where a higher mode of respiratory support can be introduced.

[0041] Gas flows from the outer chamber 102 into the reservoir 104 via the connector 107 . Figure 1The arrows in the figure indicate the flow of gas. The reservoir 104 is configured to store gas received from the outer chamber 102 when not needed by the user. If the patient interface 101 fits the user correctly, there will be no loss of airflow, and all of the gas delivered to the outer chamber 102 will flow into the reservoir 104, indicating that the device 100 is working efficiently.

[0042] In some embodiments, the volume of reservoir 104 can be variable. For example, reservoir 104 can be configured to visibly expand when gas flows from outer chamber 102 into reservoir 104 via connector 107. If the airflow is sufficient to meet the patient's needs, reservoir 104 is filled and expanded, providing a visual indication of proper performance. Failure of reservoir 104 to expand may indicate a problem with the flow of gas from outer chamber 102, or that the user's breathing pattern requires a higher gas flow rate from an external supply. In this way, direct observation of the device 100 in use informs the accompanying medical professional whether the device is functioning correctly, allowing corrective measures to be taken. As described above, observing the expansion of outer chamber 102 further supports this. Because proper application to the user is inherent to the function of device 100, the present invention overcomes the known problem of gas leakage caused by prior art devices due to poor fit with the user.

[0043] The connector 107 is configured to receive a flow of gas from the outer chamber 102. The connector 107 includes one or more openings to allow gas exchange between the connector 107 and the reservoir 104. The one or more openings can be evenly or unevenly spaced. For example, the connector 107 can include four openings spaced 90° apart around the periphery of the connector 107. The connector 107 can take any suitable shape. In some embodiments, the connector 107 is a cylindrical connector.

[0044] Device 100 may also include an anti-asphyxia valve 108 connected to connector 107. Anti-asphyxia valve 108 is configured to remain closed when the gas pressure in connector 107 equals or exceeds ambient pressure. On the other hand, when the gas pressure in connector 107 is lower than ambient pressure, anti-asphyxia valve 108 is configured to open, allowing the surrounding atmosphere to flow into device 100, allowing the user to breathe freely. In this way, the user is protected from gas flow failures through device 100, for example, if the external supply fails or the supplied gas flow rate is insufficient to meet the user's breathing pattern.

[0045] Figure 7 Shown are example structures of the connector 107 and the anti-asphyxia valve 108. The connector 107 and the anti-asphyxia valve 108 are attached to a mount 701 which is secured to the outer bag 501 in an airtight manner.

[0046] The device 100 also includes an internal chamber 103 in fluid communication with the user's airway. When the user inhales, gas is drawn from the reservoir 104 into the internal chamber 103 through one or more inhalation valves 109.

[0047] The reservoir 104 is configured to store gas received from the outer chamber 102 when the one or more inhalation valves 109 are closed. The one or more inhalation valves 109 are configured to open when the pressure of the gas in the reservoir 104 is higher than the pressure of the gas in the inner chamber 103 to allow gas to flow from the reservoir 104 into the inner chamber 103. For example, the one or more inhalation valves 109 can be configured to open during an exhalation pause and / or when the user inhales.

[0048] When the user exhales, gas flows out of device 100 via exhalation valve 110. Exhalation valve 110 is configured to open when the gas pressure in internal chamber 103 exceeds ambient pressure to allow gas to flow out of device 100. For example, exhalation valve 110 can be configured to open when the user exhales.

[0049] Figure 8 An example structure of the inhalation valve 109 and the exhalation valve 110 is shown. The inhalation valve 109 and the exhalation valve 110 are attached to a mount 801 which is secured in an airtight manner to the inner bag 502. The outer bag 501 is secured in an airtight manner around the outer edge of the exhalation valve 110.

[0050] As an example, consider a user's breathing pattern. Figure 9 is a flow chart detailing the flow of gas through the device during a user's breathing pattern. The steps on the left side of the diagram illustrate the user's actions, while the steps on the right side illustrate the operation of the device. At 901, the user inhales. As the user inhales, the pressure in the internal chamber 103 decreases, causing the gas pressure in the internal chamber to be lower than the gas pressure in the reservoir 104 and the ambient pressure. Consequently, at 902, one or more inhalation valves 109 open, and the exhalation valve 110 closes. At 903, gas is drawn from the reservoir 104 into the internal chamber 103 to form the user's inhaled breath.

[0051] At 904, the user exhales. As the user exhales, the pressure in the internal chamber 103 increases, causing the gas pressure in the internal chamber to exceed the gas pressure in the reservoir 104 and the ambient pressure. Consequently, at 905, the one or more inhalation valves 109 close, and the exhalation valve 110 opens. At 906, the exhaled gas flows out of the device 100 via the exhalation valve 110.

[0052] At 907, the user stops exhaling (expiratory pause). Once the user stops exhaling, at 908, one or more inhalation valves 109 open and gas flows from the reservoir 104 into the inner chamber 103 (909). This flow of gas is sufficient to prevent the exhalation valves from closing. After the user has exhaled and the inhalation valves 109 have opened to allow gas to enter the inner chamber 103, the pressure within the inner chamber 103 may be slightly positive. In one embodiment, the pressure within the inner chamber 103 does not exceed the ambient pressure of 981 Pa.

[0053] At 910, the airflow forces any remaining exhaled gas out of the inner chamber 103 through the exhalation valve 110, thereby venting the inner chamber 103 before the next inhalation. This ensures that the user's next inhalation contains only supplied gas and does not contain any exhaled gas, particularly exhaled carbon dioxide. The pressure in the inner chamber 103 will depend on the flow rate entering the inner chamber 103 and thereby venting it through the exhalation valve 110. Therefore, the pressure in the inner chamber 103 will be determined by the flow resistance of the exhalation valve 110.

[0054] In normal operation, once the user inhales, if the gas is supplied at a pressure consistent with the user's breathing pattern, the pressure in the inner chamber 103 will drop below the ambient pressure. Therefore, the inner chamber 103 collapses during inhalation.

[0055] The effect of this design is to ensure that the airflow adjustment for the user's breathing needs is accurate, which in turn makes the mask efficient. Figure 10a Results of experiments using the current industry standard high concentration non-rebreathing oxygen mask are shown. In particular, Figure 10a Shows the gas composition received over time as a percentage of the total gas volume received by the user when using the current industry standard high concentration non-rebreathing oxygen mask. The mask supplies 100% oxygen. Figure 10a As can be clearly seen in the diagram, the user only receives about 70% oxygen, with the remainder made up of nitrogen from the ambient air. Therefore, the user is actually only receiving a small portion of the supplied gas.

[0056] Figure 10b The same experiment is shown, but this time using the device of the present invention. The experiment was carried out under the same conditions as the current industry standard high concentration non-rebreathing oxygen mask. Initially, the user breathes ambient air (78% nitrogen, 21% oxygen, trace carbon dioxide). At 1 minute, the gas supply of 100% oxygen is turned on and the resulting gas received by the user quickly equilibrates to nearly 100% oxygen and trace nitrogen. At 13 minutes, the gas supply is cut off and the user returns to breathing ambient air. Therefore, when using the device according to the present invention, the user receives close to 100% supply gas. It is clear that the present device provides more precise airflow regulation for the user's breathing needs.

[0057] Compared to the prior art shield devices described above, the device according to the present invention requires significantly less airflow (approximately 1.5 x patient-minute volume compared to 5 x patient-minute volume for conventional shield devices).

[0058] Return to Figure 1 The exhalation valve 110 may also include a filter configured to filter the exhaled gas as it exits the device 100. Because the patient interface 101 is shaped to the user's face to close one or more exhaust holes 105, the user's respiratory tract is isolated, forcing all exhaled gas to pass through the exhalation valve. Therefore, providing a filter in the exhalation valve 110 can prevent the continued spread of airborne microorganisms that may be present in the exhaled gas. This also facilitates microbial sampling and capture of exhaled microorganisms. Subsequent analysis of pathogenic microorganisms using modern molecular diagnostic techniques can improve rapid diagnosis rates and subsequent clinical decision-making regarding treatment.

[0059] The effective isolation of the respiratory tract provided by device 100 is valuable in situations where there is concern about the spread of airborne pathogens. In addition to delivering medical gases to the user, device 100 can also be used by professionals working in high-risk environments. In such situations, device 100 can be connected to a source of filtered atmospheric air.

[0060] Figure 11 Shown from different angles Figure 1 device.

[0061] Device 100 is simple to use and lightweight. It can be used by any appropriately trained user, including by patients themselves, who can then manage their own conditions. This is particularly advantageous if device 100 is used to administer inhaled medication, for example, by using a helium / oxygen mixture to aid in the delivery of aerosolized medication to the lungs.

[0062] Various modifications and variations that fall within the scope of the appended claims will become apparent to those skilled in the art.

Claims

1. A device for delivering gas to a user, comprising: a patient interface configured to surround a user's mouth and nose; an outer chamber configured to receive gas from an external supply, wherein the outer chamber is secured to a patient-facing side of the patient interface and includes one or more vents, wherein the one or more vents are configured to close when the device is secured to a user; a reservoir in fluid communication with the outer chamber; a connector configured to receive a flow of gas from the outer chamber, the connector comprising one or more openings to allow gas exchange between the connector and the reservoir; an inner chamber in fluid communication with the user's airway; one or more suction valves configured to allow gas to flow from the reservoir into the inner chamber when the pressure of the gas in the reservoir is higher than the pressure of the gas in the inner chamber; and An exhalation valve is configured to allow gas to flow out of the device when the pressure of the gas in the internal chamber exceeds the ambient pressure.

2. The device according to claim 1, wherein An outer wall of the outer chamber is continuously attached to the patient interface, and an inner wall of the outer chamber is spaced apart and attached to the patient interface to form the one or more vents.

3. The device according to any one of the preceding claims, wherein The one or more vents are configured to be open when the device is not secured to the user.

4. The device of any one of the preceding claims, further comprising an anti-asphyxia valve connected to the connector, the anti-asphyxia valve being configured to remain closed when the gas pressure in the connector equals or exceeds ambient pressure. 5 . The device of claim 4 , the anti-asphyxia valve being configured to open when the gas pressure in the connector is lower than the ambient pressure.

6. A device according to any one of the preceding claims, wherein The volume of the outer chamber is variable, and wherein the outer chamber is configured to expand upon receiving gas from an external supply when the one or more vents are closed.

7. A device according to any one of the preceding claims, wherein The reservoir is configured to store gas received from the connector when the one or more inhalation valves are closed.

8. A device according to any one of the preceding claims, wherein The one or more inhalation valves are configured to open during an expiratory pause.

9. The device according to any one of the preceding claims, wherein The one or more inhalation valves are configured to open when the user inhales.

10. The device according to any one of the preceding claims, wherein The exhalation valve is configured to open when the user exhales.

11. The device according to any one of the preceding claims, wherein The patient interface is deformable.

12. The device according to claim 11, wherein The patient interface is elastic.

13. The device according to claim 11 or 12, wherein: The patient interface comprises memory foam.

14. The device of any preceding claim, further comprising one or more straps configured to hold the device in place during use.

15. The device according to claim 14, wherein The one or more straps are quick release straps.

16. The apparatus of any preceding claim, further comprising a medical gas connector for connection to an external gas supply.

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