The present disclosure relates to apparatus for use in a dry powder inhaler (DPI) and dry powder inhalers comprising such apparatus. The apparatus may comprise a trigger assembly and a valve used for controlling a compressed air lumen.
According to a first aspect of the present disclosure there is provided a suction actuated valve, for a dry powder inhaler, comprising: a compressed air lumen; a control chamber for providing suction; and a trigger assembly, in fluid communication with the control chamber, comprising: a displaceable membrane contained within the control chamber and displaceable within the control chamber, the displaceable membrane configured to seal the control chamber such that suction provided by the control chamber displaces at least a portion of the displaceable membrane to provide an opening force to the trigger assembly for moving the trigger assembly from a closed configuration to an open configuration; and a trigger coupled to the displaceable membrane, the trigger configured, in the closed configuration, to occlude the compressed air lumen and configured, in the open configuration, to open the compressed air lumen; wherein the trigger may have a first cross-sectional area and the displaceable membrane may have a second cross-sectional area greater than the first cross-sectional area such that when suction is provided by the control chamber the displaceable membrane may provide a mechanical advantage for moving the trigger from the closed configuration to the open configuration.
Provision of such a mechanical advantage may advantageously enable relatively weak suction to actuate the suction actuated valve.
In one or more embodiments the displaceable membrane may be configured to apply a biasing force to the trigger in an opposing direction to the opening force.
In one or more embodiments the trigger may be coupled to a region of the displaceable membrane that is proximal to a geometric centre of the displaceable membrane.
In one or more embodiments the control chamber seal may provide a gas-tight seal of the control chamber.
In one or more embodiments the compressed air lumen may comprise an elastic tube and in the closed configuration, the trigger assembly is configured to compress the elastic tube to occlude the compressed air lumen and in the open configuration the trigger assembly is configured to decompress the elastic tube to open the compressed air lumen.
In one or more embodiments the trigger assembly may comprise a pushing bar configured to move from an occluding position to an open position, the pushing bar having a distal end and a proximal end, the proximal end configured to compress the elastic tube when in the occluding position to occlude the compressed air lumen and configured to decompress the elastic tube when in the open position to open the compressed air lumen.
In one or more embodiments the elastic tube may be configured to provide a biasing force to move the pushing bar from the occluding position to the open position when the trigger assembly moves from the closed configuration to the open configuration.
In one or more embodiments the trigger may comprise a distal end and a proximal end, the distal end coupled to the displaceable membrane and the proximal end configured to engage mechanically with the pushing bar when in the closed configuration to latch the pushing bar in the closed position and configured to disengage from the pushing bar when in the open configuration to enable the pushing bar to move to the open position.
In one or more embodiments the pushing bar may comprise a latching feature between the proximal end and the distal end, the latching feature configured to engage with the proximal end of the trigger when in the closed configuration to latch the pushing bar in the closed position.
In one or more embodiments the displaceable membrane may be configured to apply a biasing force to the trigger to engage the trigger with the pushing bar when the trigger assembly is in the closed configuration.
In one or more embodiments the occlusion of the compressed air lumen may provide a gas-tight seal of the compressed air lumen.
In one or more embodiments the suction actuated valve may be further configured to be coupled to a compressed air source and to contain compressed air when in the closed configuration.
In one or more embodiments the suction actuated valve may be further configured to be coupled to a drug feeder and to provide a predetermined amount of compressed air to the drug feeder when the trigger assembly moves from the closed configuration to the open configuration.
In one or more embodiments the control chamber may be configured for connection to a mouthpiece of an inhaler such that a user may provide suction to the control chamber via the mouthpiece.
In one or more embodiments a dry powder inhaler may comprise the suction actuated valve.
One or more embodiments will now be described by way of example only with reference to the accompanying drawings in which:
A dry powder inhaler (DPI) is a medical device for delivering medicament in the form of a dry powder into a user's lungs. In some examples, the dry powder medicament may be aerosolised by energy provided by a user's inhalation. In other examples, some auxiliary energy, additional to that arising from a user's inhalation, may be provided to aerosolize a dry powder medicament. Such auxiliary energy may advantageously provide an aerosolised dry powder that a user may inhale more easily and more deeply into their lungs, where the medicament may be more efficacious.
The trigger 3 is suction-actuated and configured to be controlled by a user. The third valve 23 is used to control the air path between the mouthpiece 1 and the trigger 3. The third valve 23 is coupled to the drug feeder 2 in a manner that it only opens when a dose of drug powder has been properly fed.
To use this DPI 10, the user needs to charge the gas reservoir 5 to a pre-set pressure using the pump 11. Upon the increase of the air pressure of gas reservoir 5, sensor 6 receives a signal and automatically makes trigger 7 engage timer 8 and shut the second valve 9. The trigger 7 controls the second valve 9. The timer 8 controls the trigger 7. The second valve 9 controls the passage of fresh air from the outside atmosphere that is external to the DPI 10 through to the user's mouth. The user then manually feeds the drug powder properly and at the same time opens the third valve 23. DPI 10 is thereby configured ready for use.
When the user starts to inhale from the mouthpiece 1, there is no fresh air available from the outside atmosphere as both the first valve 4 and the second valve 9 are closed. The first valve 4 controls the release of pressurized air contained in the gas reservoir 5. The suction force drives the trigger 3 to open the first valve 4 while the second valve 9 is still closed. The pressurized air in the reservoir 5 then goes through the first valve 4 and into the drug feeder 2 where it disperses the drug powder to form an aerosol. The aerosolised powder is then driven into the mouthpiece 1 where its passage way becomes wider than that in the drug feeder. The speed of the aerosolised particles is thereby reduced. The air in the mouthpiece 1 is not moving although the user is sucking; as there is no further supply of fresh air, which becomes available only after the second valve 9 is opened. In this way the speed of the aerosolised particles is further reduced whereas the dispersion is further improved because of strong friction among the flying particles and the still air. The sensor 6 senses a signal upon release of pressurized air from the reservoir 5. At a certain point, the sensor 6 actuates the timer 8 and drives the trigger 7 to a relaxed state. The timer 8 holds the trigger 7 for a pre-set time and then releases it. The second valve 9 is then opened to allow the fresh air to be provided to the mouthpiece. The aerosolised drug particles then follow the inhaled fresh air to a targeted area in the user's lung.
The suction actuated valve shown in
More generally, a suction actuated valve according to the present disclosure may comprise: a compressed air lumen; a control chamber for providing suction; and a trigger assembly in fluid communication with the control chamber.
The compressed air lumen may be configured to supply compressed air to the suction actuated valve. When the suction actuated valve is in an open configuration the compressed air lumen may be configured to supply compressed air through the suction actuated valve for aerosolisation of a dry powder medicament, for example.
The control chamber may comprise a void space (such as the void space 343 of
The trigger assembly may be configured to move from a closed configuration to an open configuration in response to suction provided by the control chamber. In the closed configuration the trigger assembly may be configured to occlude the compressed air lumen. In some examples the occlusion of the compressed air lumen in the closed configuration may be complete and provide for a gas tight seal of the compressed air lumen. In other examples, the closed configuration may provide incomplete occlusion of the compressed air lumen; a small amount of leakage of compressed air through the suction actuated valve in its closed configuration may be acceptable. In the open configuration the trigger assembly may be configured to open the compressed air lumen. In some examples the compressed air lumen may be completely open in the open configuration while in other examples the compressed air lumen may only be partially open when in the open configuration, such that at least a pre-determined volume of compressed air may be supplied though the compressed air lumen.
The trigger assembly may comprise a displaceable membrane contained within the control chamber and displaceable within the control chamber. A rim portion of the displaceable membrane may optionally be coupled to the control chamber such that the coupled rim portion is not displaceable. In some examples only a portion of the displaceable membrane may be moveable within the control chamber. The displaceable membrane may be configured to seal the control chamber such that suction provided to the control chamber displaces at least a portion of the displaceable membrane. In some examples the displaceable membrane may be configured to seal the control chamber by providing for a gas-tight seal of at least a portion of the control chamber. In other examples, the displaceable membrane may only partially seal the control chamber such that suction provided to the control chamber may cause some small amount of leakage of gas past the displaceable membrane. The displaceable membrane may be configured to provide an opening force to the trigger assembly for moving the trigger assembly from the open configuration to the close configuration. It will be appreciated that a small amount of leakage may still enable the displaceable membrane to move the trigger assembly, while a gas-tight seal may advantageously enable a lower amount of suction to achieve the same movement of the trigger assembly.
The trigger assembly may further comprise a trigger coupled to the displaceable membrane. The trigger may be configured, in the closed configuration, to occlude the compressed air lumen and configured, in the open configuration, to open the compressed air lumen. The trigger may have a first cross-sectional area and the displaceable membrane has a second cross-sectional area greater than the first cross-sectional area such that when suction is provided by the control chamber the displaceable membrane may provide a mechanical advantage for moving the trigger from the closed configuration to the open configuration. The trigger may be advantageously coupled to the displaceable membrane at or proximal to the geometric centre of the displaceable membrane, and away from the rim portion of the membrane. Coupling at or near the geometric centre may enable greater mechanical advantage as the centre of the membrane may be configured to move further than parts of the membrane proximal to the rim portion. This mechanical advantage may enable a relatively weak level of suction provided by the user to actuate the trigger assembly and thereby the suction actuated valve.
In some examples, the displaceable membrane may be configured to apply a biasing force to the trigger in an opposing direction to the opening force. The opposing direction need not be exactly opposite to the opening force. The biasing force may comprise at least one component that is diametrically opposite to the direction of the opening force. Thereby, the displaceable membrane may provide the biasing force to move the trigger assembly into the closed configuration when little or no suction is provided to the control chamber and may also provide the opening force to move the trigger assembly into the open configuration when adequate suction is provided to the control chamber. In this way it is advantageously possible to provide both the opening force and the biasing force using the same component, namely the displaceable membrane.
In some examples, where the compressed air lumen comprises an elastic tube, in the closed configuration the trigger assembly may be configured to compress the elastic tube to occlude the compressed air lumen. This compression may be partial or total, to provide for a partial seal or a gas-tight seal. In the open configuration the trigger assembly may be configured to decompress the elastic tube to open the compressed air lumen. The decompression of the elastic tube may be partial or total. In some examples the decompression may be provided by the elastic properties of the elastic tube, which may be biased to form an open configuration when a force applied by the trigger assembly is reduced or removed.
The trigger assembly may comprise a pushing bar configured to move from an occluding position to an open position, the pushing bar having a distal end and a proximal end, the proximal end configured to compress the elastic tube when in the occluding position to occlude the compressed air lumen and configured to decompress the elastic tube when in the open position to open the compressed air lumen.
In some examples, the control chamber may comprise a distal end and a proximal end. The distal end of the control chamber may be coupled to the mouthpiece of an inhaler.
The trigger assembly may comprise a trigger having a distal end and a proximal end, the distal end coupled to the displaceable membrane and the proximal end configured to engage mechanically with the pushing bar when in the closed configuration to latch the pusher bar in the closed position and configured to disengage from the pusher bar when in the open configuration to enable the pusher bar to move to the open position. In some examples the trigger may engage with the pushing bar by frictional forces alone.
In some examples the pusher bar may comprise a latching feature between the proximal end and the distal end, the latching feature configured to engage with the proximal end of the trigger when in the closed configuration to latch the pusher bar in the closed position. The proximal end of the trigger may have a complementary latching feature configured to engage with the latching feature of the pusher bar, to latch the pusher bar in the closed configuration.
The displaceable membrane may be configured to apply a biasing force to the trigger to engage the trigger with the pushing bar when the trigger assembly is in the closed configuration.
The suction actuated valve of the present disclosure may be further configured to be coupled to a compressed air source and to contain compressed air when in the closed configuration, on a compressed air storage side of the suction actuated valve. A suitable compressed air source may be a compressed air chamber with a pre-determined volume configured to contain compressed air at a pre-determined pressure.
The suction actuated valve may have a compressed air delivery side opposite to the compressed air storage side. The compressed air delivery side may be configured to be coupled to a drug feeder and to provide a predetermined amount of compressed air to the drug feeder when the trigger assembly moves from the closed configuration to the open configuration. In this way, the potentially highly variable suction force provided by a user may initiate supply of a precisely pre-determined volume and pressure of compressed air to the drug feeder, the volume and pressure selected to provide appropriate aerosolisation of dry powder medicament contained within the drug feeder. Advantageously, different pre-determined volumes and pressures of compressed air may be selected for use with different dry powder medicaments, in accordance with the particular properties of the medicament concerned. Thereby, a dry powder inhaler may advantageously comprise the suction actuated valve of the present disclosure.
More generally, an apparatus for a dry powder inhaler may comprise: a compressed air chamber; an occluder for occluding a fresh air inlet of a dry powder inhaler; an elastic membrane in fluid communication with the compressed air chamber and coupled to the occluder. For example, the elastic membrane may form a wall of the compressed air chamber, configured to contain compressed air within the chamber. The elastic membrane may be considered an example of a sensor because the membrane is sensitive to the pressure within the compressed air chamber and will change its shape in response to changes in the pressure within the compressed air chamber relative to the pressure outside of the compressed air chamber. In some examples, the occluder may comprise a portion of the elastic membrane.
The elastic membrane may be configured to move the occluder to a closed position, in sealing engagement with the fresh air inlet, in response to an air pressure within the compressed air chamber to occlude the fresh air inlet. Occlusion of the fresh air inlet may be provided if the fresh air inlet is disposed proximal to the elastic membrane such that as the elastic membrane changes shape in response to changes in pressure in the compressed air chamber, the occluder is brought into sealing engagement with the fresh air inlet. Further, the apparatus may be configured to move the occluder to an open position, disengaged from the fresh air inlet, in response to a reduction of the air pressure to open the fresh air inlet.
The sealing engagement of the occluder with the fresh air inlet may advantageously provide for a gas tight seal of the fresh air inlet. Alternatively, the occlusion may be only partial such that a small amount of ingress of fresh air may be allowed while in the closed position.
In some examples the occluder may comprise a conical part for engaging with an aperture of the fresh air inlet to occlude the fresh air inlet when in the closed position.
The conical part may be configured to be inserted into the fresh air aperture to form a sealing engagement with an interior surface of the fresh air inlet. When inserted into the fresh air aperture the conical part may automatically centre the occluder with respect to the fresh air inlet.
In some examples, the occluder comprises a shoulder for engaging with the fresh air inlet to occlude the fresh air inlet when in the closed position. The shoulder may be configured to engage with an exterior surface of the fresh air inlet. When the occluder comprises a conical part and, disposed coaxially around the conical part, a shoulder, the action of the conical part in centring the occluder with respect to the fresh air inlet may advantageously engage the shoulder with an appropriate part of the exterior surface of the fresh air inlet to improve the sealing engagement between the occluder and the fresh air inlet.
The apparatus may further comprise a fresh air inlet comprising: a fresh air aperture; and an inlet surface surrounding the fresh air aperture. Thereby, the apparatus may be configured such that the elastic membrane and occluder are proximal to the fresh air inlet aperture. The elastic membrane may be surrounded by a chamber surface of the compressed air chamber, wherein the chamber surface may be spaced from the inlet surface by a distance of 0.5 mm to 25 mm. In some examples the chamber surface may be spaced apart from the inlet surface by a distance of 1 mm to 10 mm, or preferably a distance of 2 mm to 8 mm. These spacings may provide for adequate air flow into the fresh air inlet when the occluder is in the open position, while enabling the occluder to form a sealing engagement with the fresh air inlet when in a closed position.
The compressed air chamber may further comprises a check valve configured to enable supply of compressed air into the compressed air chamber and to seal to prevent or reduce leakage of compressed air from the compressed air chamber. The seal against such leakage may or may not comprise a gas-tight seal.
The apparatus may further comprise a trigger valve in fluid communication with the compressed air chamber, wherein the trigger valve is configured to occlude leakage of air from the compressed air chamber until actuation of the trigger valve by a user, and upon actuation is configured to release a predetermined quantity of compressed air and thereby to provide for the reduction of the air pressure. The reduction in the air pressure may be suitable for moving the occluder from the closed position to the open position. In some examples, the apparatus may comprise a control chamber with a distal end and a proximal end, the distal end coupled to a mouth piece for a dry powder inhaler and the proximal end coupled to the trigger valve, wherein the trigger valve is configured to be actuated by suction provided to the mouthpiece by a user, as described above.
The apparatus may further comprising a drug feeder in fluid communication with the trigger valve, wherein on actuation of the trigger valve the drug feeder is configured to receive a pre-determined quantity of compressed air for aerosolizing a dry powder medicament, as previously described above.
The apparatus may further comprise a mouthpiece with a distal end and a proximal end, the mouthpiece configured to: receive, at the proximal end at a first velocity, a predetermined quantity of aerosolised dry powder medicament from the drug reservoir; and provide at least a portion of the predetermined quantity of aerosolised dry powder medicament to the distal end at a second velocity that is lower than the first velocity. The portion of the predetermined quantity may be a first portion, that may be followed at a later time by some or all of a remainder portion of the predetermined quantity of aerosolised dry powder medicament.
The elastic membrane may be configured to move the occluder out of sealing engagement with the fresh air inlet a pre-determined time after the reduction of air pressure in the compressed air chamber, based on the elasticity of the elastic membrane. The greater the elastic restoring force provided for by the membrane the shorter the predetermined time may be. In some examples the fresh air inlet may be coupled to the mouthpiece and the pre-determined time may be selected such that fresh air from the fresh air inlet is provided to the mouthpiece after the portion of the predetermined quantity of aerosolised dry powder medicament is provided to the distal end of the mouthpiece. In this way, a user inhalation may provide for a precisely controlled release of dry powder medicament before the user inhales fresh air via the fresh air inlet. The provision of the aerosolised dry powder before the fresh air may enable the user to inhale the medicament more deeply into their lungs than other examples where the medicament may be provided during the middle of an inhalation. This deeper inhalation of the medicament may enable more effective treatment of lung conditions as the medicament may reach parts of the lungs where it can be more efficacious. Thereby, a dry powder inhaler may advantageously comprise the apparatus of the present disclosure.
To use such an active DPI, a user needs to push the pushing bar 350 to close the compressed air channel 411. The biasing force of elastic part 320 drives the trigger part 330 towards the pushing bar 350 to a position of closing the compressed air channel 411. The user then charges the gas reservoir 514 using the pump 11 that compromise of a cylinder 1110, a handle 1120 and a piston 1130 (details not shown). Upon charging, the pressure in gas reservoir 514 increases. The positive pressure in reservoir 514 pushes the elastic sensor 610 upwards to make the conical part 611 in airtight contact with the fresh air aperture 921 and the shoulder 612 in close contact with a smooth surface 924, which in turn closes the fresh air aperture 921. After a certain pressure in the gas reservoir is reached, the user feeds a unit dose of drug to air channel 213 and then starts inhaling through air channel 111. As both the fresh air aperture 921 and the compressed air channels 411, 412 and 413 are closed, the drug feeder is an airtight compartment when covered using a lid 220; and the trigger tube 343 just connects the mouthpiece to an airtight enclosed void space 343, therefore there is no fresh air or compressed air provided to the user's mouth. The suction produces a negative pressure in the void 343. When the negative pressure increases to a certain pre-determined value, the force exerted onto the elastic part 320 is big enough to displace the trigger to open the elastic tube 410. The elastic biasing force of the elastic tube 410 then pushes the pushing bar downwards as shown in the right diagram of
It will be appreciated that embodiments of the apparatus disclosed herein may also be embedded in other types of inhaler in addition to dry powder inhalers as disclosed above.
It will be appreciated that any components said to be coupled may be coupled or connected either directly or indirectly. In the case of indirect coupling, additional components may be located between the two components that are said to be coupled.
In this specification, example embodiments have been presented in terms of a selected set of details. However, a person of ordinary skill in the art would understand that many other example embodiments may be practised which include a different selected set of these details. It is intended that the following claims cover all possible example embodiments.
Number | Date | Country | Kind |
---|---|---|---|
GB1511950.6 | Jul 2015 | GB | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/GB2016/000131 | 6/28/2016 | WO | 00 |