AEROSOL GENERATOR

Description

[0001] The invention relates to an aerosol generator with an active liquid container and a nebulization chamber associated therewith, which is connected to an inlet channel for supplying carrier gas and to an outlet channel for discharging carrier gas mixed with aerosol obtained from the active liquid.

[0002] Aerosol generators of this type can be used, for example, in so-called inhalers to nebulize a liquid active ingredient or a drug or to generate fine and extremely fine droplets from it. In the form of an aerosol generated in this way, the active ingredient or drug can then be mixed with a patient's exhaled air and introduced into the respiratory tract via the exhaled air. Such administration of active ingredients or drugs via the exhaled air into the respiratory tract can be very effective and efficient, as rapid and minimal transfer from the lungs into the bloodstream can occur.

[0003] It is also known from WO 2012 / 079684 A1 that drug aerosols generated by such an aerosol generator can be administered as part of transnasal inhalation therapy. With appropriate implementation, i.e., particularly with comparatively slow administration and a particularly small droplet size, deposition of the drug relatively deep in the lungs and thus efficiently at the desired site of action, namely the lung periphery, is possible. Especially for such applications, it is desirable to be able to adjust and control the droplet size of the droplets generated in the aerosol generator particularly precisely when nebulizing the drug.

[0004] WO 2010 / 149144 A1 discloses an aerosol generator of the above-mentioned type, which is intended to enable the reliable generation of aerosol droplets with a small droplet size while minimizing flow resistance for breathing. For this purpose, the known aerosol generator comprises a substantially cylindrical nebulization chamber. The carrier gas flowing into this chamber, in particular the patient's breathing air, is swirled around the cylinder axis by a guide vane arrangement in the nebulization chamber, where the aerosol obtained from the active liquid is also "loaded." Due to centrifugal force, the comparatively large and correspondingly heavy aerosol droplets are pressed against the inside of these guide vanes, where they agglomerate and separate into droplets, so that they are returned along the housing wall to the active ingredient container.With this arrangement, the supply of undesirably large aerosol droplets to the outlet channel of the aerosol generator can be limited; however, further control or even targeted adjustment of a desired droplet size in the aerosolized breathing air emitted from the outlet side is not possible with this system.

[0005] US2016 / 256637A1 discloses a metered-dose inhaler with an ultrasonic nebulizer comprising an aerosol dome in which a baffle plate is arranged, and an air supply tube that enters the aerosol dome to create a vortex flow. The aerosol dome is fixedly connected to and covered by an exhaust tube and a dome arranged concentrically to the aerosol dome. The exhaust tube is connected to a mouthpiece.

[0006] WO00 / 15282A1 discloses an ultrasonic nebulizer comprising a chamber, a baffle plate, and a central tubular structure connected to a delivery tube. The chamber is supplied with pressurized gas from a pre-chamber via two tangential channels. The alignment of the channels creates a rapid, circular or vortex-like flow of gas in the chamber, which mixes with a coarse aerosol, creating a piezoelectric disc.

[0007] The invention is therefore based on the object of specifying an aerosol generator of the type mentioned at the outset with which the droplet size of the aerosols contained in the emitted carrier gas can be particularly well adjusted and which is thus particularly suitable for use in the context of transnasal inhalation therapy.

[0008] This problem is solved by the features of independent claim 1.

[0009] Advantageous embodiments of the invention are the subject of the subclaims.

[0010] The invention is based on the idea that by utilizing rotation or swirl of the aerosol-laden carrier gas flowing through the nebulization chamber to depose undesirably large aerosol droplets on the boundary wall, the adjustability of the droplet size can be further improved by providing an additional degree of freedom for influencing the centrifugal force-induced deposition. To make this possible, the swirl or rotation of the carrier gas flowing through the nebulization chamber is generated independently of static fixtures within the nebulization chamber. This can be achieved in a particularly simple manner by designing the aerosol generator for off-center feeding of the carrier gas into the nebulization chamber, i.e., offset from the rotation or symmetry axis of the nebulization chamber.The carrier gas should therefore be fed into the nebulization chamber in an inflow direction that has a tangential component relative to its rotation axis upon entry into the nebulization chamber. This allows the swirl and thus the angular velocity of the carrier gas's rotation within the nebulization chamber to be influenced by adjusting or controlling the carrier gas's inflow parameters, such as volume flow and / or velocity. In particular, this allows the gas and / or aerosol to be set into rotation in a controlled manner.

[0011] Advantageously, the inlet channel of the nebulization chamber is connected to a pump unit, in particular a fan or blower, on the inlet side. The pump unit is advantageously adjustable in terms of its flow rate, so that the inflow rate and / or velocity of the carrier gas flowing into the nebulization chamber can be adjusted. This also allows, in particular, the aerosol size, i.e., the average size of the aerosol droplets, to be regulated.

[0012] The active liquid can be nebulized using any suitable nebulizer, for example, a jet nebulizer. According to the invention, an ultrasonic nebulizer is provided for this purpose. This nebulizer preferably comprises a piezoelectric crystal of a known design that generates ultrasound. The ultrasound is transmitted to the active liquid in the active liquid container, forming a bubble on its surface from which fine droplets are released as an aerosol.

[0013] When the active liquid is atomized, particularly by ultrasound, a liquid column can form above the liquid level, particularly in the bubbling that forms. In order to limit this height using simple means and to ensure the separation of particularly large liquid droplets in a particularly simple manner, a baffle plate is arranged in the atomization chamber opposite the active liquid container. The largest liquid droplets in particular are deposited on this plate so that they can drip back from the baffle plate into the active liquid container. According to the invention, the distance between the baffle plate and the active liquid container or the surface of the active liquid is adjustable so that the height of the liquid column and the droplet separation can be influenced in a particularly simple manner depending on requirements and operating mode.In particular, the particle size of the resulting aerosol can be particularly effectively influenced in the combination, which is considered to be particularly advantageous and independently inventive, of an adjustable distance between the baffle plate and the active liquid on the one hand and the adjustable feed rate of the carrier gas into the nebulization chamber on the other.

[0014] This can be achieved in a particularly simple manner by arranging the baffle plate in front of the inlet opening of the outlet channel and at a distance from it.

[0015] A particularly simple and therefore cost-effective design is achieved in that the outlet channel is formed by an outlet pipe which is guided through a cover flange of the atomization chamber so that it can be displaced in its longitudinal direction. In particular, the outlet pipe can be screwed into the cover flange using a thread, so that rotation of the outlet pipe in the cover flange is converted into a displacement in the longitudinal direction via the thread. Particularly preferably, the baffle plate is attached to the end of the outlet pipe, for example via webs, at a distance from the inlet opening of the outlet pipe, so that by displacing the outlet pipe in the cover flange, for example by turning it, the height of the positioning of the baffle plate above the active liquid can also be changed. Such height adjustment, for example by turning it, can be carried out manually.Increased precision can be achieved in such a system by providing an automated height adjustment, for example, via a stepper motor. This can directly influence the linear positioning of the impact plate mounted on the outlet pipe or can also be achieved by rotating the outlet pipe, thus effecting the height adjustment via the thread.

[0016] Advantageously, the outlet channel, at least in the area where it enters the nebulization chamber, is oriented longitudinally substantially parallel to the cylinder or symmetry axis of the nebulization chamber, so that the carrier gas laden with the aerosol flows out of the chamber in a direction substantially parallel to the rotational axis of the nebulization chamber. Relative to the cylinder coordinate system of the nebulization chamber, the outflow of the carrier gas thus occurs substantially in an axial direction and thus orthogonal to the tangential directional component of the inflowing carrier gas. This allows the desired swirl to be generated and adjusted particularly effectively via the flow conditions of the carrier gas in the nebulization chamber.

[0017] In a particularly advantageous embodiment, oxygen or an oxygen-containing gas is provided as the carrier gas, making the carrier gas particularly suitable as a breathing gas for the patient or user. The oxygen-containing carrier gas can be supplied from the nebulization chamber, for example, by an oxygen supply or an oxygen concentrator. To enable this, the nebulization chamber and / or the fan or blower upstream of it on the gas side are expediently connected on the inlet side to an oxygen supply or an oxygen concentrator.

[0018] In a further advantageous embodiment, the boundary wall and / or the lid of the nebulization chamber is provided with a refill opening for the active liquid, so that the aerosol generator can be refilled with active liquid, for example, using a syringe, without requiring disassembly of the nebulization chamber. In a further particularly preferred embodiment, the nebulization chamber is connected to an external storage container or reservoir for active liquid via the refill opening or via a suitable connecting line, so that the liquid level of the active liquid and thus its liquid level can be kept constant or consistent by means of suitable refilling.

[0019] The advantages achieved by the invention are, in particular, that the eccentric supply of the carrier gas relative to the rotational axis of the nebulization chamber, particularly in conjunction with its discharge parallel to the rotational axis, allows a swirl or rotation of the gas in the nebulization chamber to be particularly effectively adjusted and easily modified. This allows the centrifugal forces acting on the gas in the nebulization chamber due to the swirl or rotation to be specifically utilized for size-dependent droplet separation and modified as needed and depending on the situation. This enables a targeted influence on the droplet size of the aerosol entrained in the outflowing carrier gas.

[0020] An embodiment of the invention is explained in more detail with reference to a drawing. In the drawing: FIG. 1 an aerosol generator in perspective view, FIG. 2 the aerosol generator according to FIG. 1 in longitudinal section, FIG. 3 the aerosol generator according FIG. 1 in exploded view, and FIG. 4 an alternative embodiment of an aerosol generator with external storage container schematically in section.

[0021] Identical parts are provided with the same reference numerals in all figures.

[0022] The aerosol generator 1 shown in the figures is designed to generate an aerosol from an active ingredient or pharmaceutical in liquid form, hereinafter referred to as the "active ingredient liquid," and to load a carrier gas with the generated aerosol or droplet mist. For this purpose, the aerosol generator 1 comprises a nebulization chamber 2 and an associated active liquid container 4, in which the active liquid to be nebulized is stored. The nebulization chamber 2 has a substantially rotationally symmetrical design with respect to its central axis, indicated by arrow 6, and is delimited in the radial direction by a substantially cylindrical boundary wall 8.

[0023] The nebulization chamber 2 is connected to an inlet channel 10 for supplying carrier gas, for example the breathing air of a patient, and to an outlet channel 12 for discharging carrier gas mixed with aerosol obtained from the active liquid.

[0024] The active ingredient container 4, which is open at the top and thus connected to the interior of the nebulization chamber 2 on the gas side, comprises a solid, annular outer wall 14 for accommodating the active ingredient or drug. The outer wall 14 is connected in the bottom region to a bottom membrane 16, preferably made of polyvinyl chloride (PVC), forming the lower closure. When assembled, the active ingredient container 4 is surrounded on the outside and bottom by a sound transmission body 18, which in turn forms an inner chamber 20 that is generally completely filled with water during operation. The PVC membrane 16 ensures that the medium to be nebulized does not mix with the water in the base tank and possibly come into contact with the nebulizer membrane. When assembled, the sound transmission body 18, in turn, sits on an ultrasonic nebulizer 22. This comprises a piezoelectric crystal 24 in a conventional design.During operation of the aerosol generator 1, the piezoelectric crystal 24 generates ultrasound, which is transmitted via the sound transmission body 18 and, in particular, via the water contained in the inner chamber 20 to the base membrane 16 of the active ingredient container 4, and then coupled into the active ingredient. The ultrasound is thus transmitted to the active liquid in the active liquid container 4 and causes it to vibrate. This causes a bubble 26 to form on its surface, from which fine droplets are released as an aerosol. This multi-component design of the aerosol generator 1 significantly facilitates cleaning during operation.

[0025] The outlet channel 12 is formed by an outlet pipe 28, which passes through a cover flange 30 of the nebulization chamber 2. The cover flange 30 seals the nebulization chamber 2 at the top. In the area of the passage, the outlet pipe 28 is provided with an external thread 32, which interacts with a corresponding internal thread in the cover flange 30. The outlet pipe 28 is screwed into the cover flange 30 via this thread combination, so that any rotation of the outlet pipe 28 in the cover flange 30 is converted into a longitudinal displacement. In the exemplary embodiment, the outlet channel 12 and, with it, the outlet pipe 28 are aligned with their longitudinal direction substantially parallel to the axis of rotation or symmetry of the nebulization chamber 2 indicated by the arrow 6, so that the carrier gas loaded with the aerosol flows out of the nebulization chamber 2 in a direction substantially parallel to the axis of rotation of the nebulization chamber 2.

[0026] As shown in particular in the sectional view in FIG. 2 can be removed, a liquid column 34 with a high droplet or liquid density is formed above the liquid level of the active ingredient in the resulting bubble 26 during operation of the aerosol generator 1. In order to limit its height and at the same time enable the separation of particularly large liquid droplets, a baffle plate 36 is arranged in the atomization chamber 2 opposite the active ingredient container 4. The largest liquid droplets, in particular, are deposited on this plate, so that they can drip back from the baffle plate 36 into the active ingredient container 4.

[0027] The baffle plate 36 is attached to the end of the outlet pipe 28, spaced from the inlet opening 38, by a number of support webs 40. This allows the height of the baffle plate 36 above the active liquid to be adjusted by moving the outlet pipe 28 in the cover flange 30, for example, by twisting it. This allows the height of the liquid column 34 and the droplet separation at the baffle plate 36 to be influenced particularly easily depending on requirements and operating mode.

[0028] The aerosol generator 1 is designed to allow particularly precise adjustment of the droplet size of the aerosols contained in the released carrier gas, thus enabling particularly good use in transnasal inhalation therapy. For this purpose, the aerosol generator 1 is configured for a carrier gas flow path within the nebulizer chamber 2, in which the carrier gas is guided along a spiral flow path and subjected to an imposed swirl. The design of the nebulizer or aerosol generator 1 is based on the concept of achieving the smallest possible aerosol particle size through particle separation using centrifugal force. A suitably supplied air flow within the cylindrical nebulizer housing is intended to cause a collision of massive aerosol particles against the nebulizer's inner wall, depending on the flow and the particle size.Thus, only comparatively smaller aerosol particles, which are important for transnasal inhalation therapy, preferably reach the outlet channel 12.

[0029] In order to enable the desired swirl or rotation generation in a particularly simple manner, a suitable supply of the carrier air into the atomization chamber 2 is provided, namely, on the one hand, an off-center supply and, on the other hand, a supply under a suitably selected feed pressure. For this purpose, the inlet channel 10 is positioned and oriented off-center in the area of its junction with the atomization chamber 2 in such a way that its longitudinal axis in the area of the junction is offset relative to the rotation axis of the atomization chamber 2 indicated by the arrow 6 and does not intersect the rotation axis. This arrangement is particularly illustrated in the perspective views in the Figuren 1 and 3 Furthermore, as can be seen from the sectional drawing in FIG. 2 The inlet channel 10 is connected on the inlet side to a pump unit 42, via which the inflow rate and / or velocity of the carrier gas flowing into the nebulization chamber 2 can be adjusted. In the exemplary embodiment, a suitably selected fan or "blower" is provided as the pump unit 42.

[0030] Through this positioning of the inlet channel 10, if necessary in combination with the adjustable feed rate of the carrier gas via the pump unit 42, the carrier gas flowing into the atomization chamber 2 is given the desired swirl around the axis of rotation. Due to centrifugal force, the comparatively large and correspondingly heavy aerosol droplets are pressed against the inner boundary wall 8 and separated there, so that they are returned along the housing wall and over the wall 44 of the atomization chamber 2, which is beveled in the lower area, into the active liquid container 4. The flow (also called volume flow), which accelerates the aerosol in the atomization chamber 2 into a circular movement, is generated in the pump unit 42, with the generated flow being regulated by changing the rotational speed of the fan / blower.

[0031] The cover flange 30 of the nebulization chamber 2 is provided with a refill opening 46 for the active liquid, so that the aerosol generator 1 can be refilled with active liquid, for example, using a syringe, without requiring disassembly of the nebulization chamber 2. Alternatively or additionally, the refill opening 46 can of course also be arranged in the boundary wall 8.

[0032] In the alternative embodiment according to FIG. 4 The active liquid container 4 of the aerosol generator 1' is connected to an external reservoir or storage container 50 for active liquid via a number of media lines 48. This reservoir or storage container 50 can be used to refill the active liquid container 4 as needed, even during operation of the aerosol generator 1', whereby, in particular, the liquid level in the active liquid container 4 can be monitored and, for example, kept constant. List of reference symbols

[0033] 1 Aerosol generator 2 Nebulization chamber 4 Active liquid container 6 Arrow 8 Boundary wall 10 Inlet channel 12 Outlet channel 14 Outer wall 16 Bottom membrane 18 Sound transmission body 20 Inner chamber 22 Ultrasonic nebulizer 24 Piezo crystal 26 Bubble 28 Outlet pipe 30 Cover flange 32 External thread 34 Liquid column 36 Baffle plate 38 Inlet opening 40 Support web 42 Pump unit 44 Wall 46 Refill opening 48 Media line 50 Storage container

Claims

1. An aerosol generator (1) with an active-liquid container (4) for an active-ingredient liquid, to which an ultrasonic nebulizer (22) on the one hand and a nebulization chamber (2) on the other hand are assigned, wherein, in the nebulization chamber (2), a fizzing (26) of the active-ingredient liquid can be generated by means of the ultrasonic nebulizer (22) above the liquid level of the active-ingredient liquid, from which fine droplets are discharged as an aerosol, wherein the nebulization chamber (2) is connected to an inlet channel (10) for the supply of carrier gas and to an outlet channel (12) for the discharge of carrier gas mixed with aerosol obtained from the active liquid, and the nebulization chamber (2) comprises an essentially rotationally symmetrical boundary wall (8), wherein the inlet channel (10) is positioned and orientated in the region of its point of entry into the nebulizer chamber (2) in such a way that its longitudinal axis in the region of the point of entry into the nebulizer chamber (2) is relative to the rotational axis or symmetry of the nebulization chamber (2) and does not intersect the rotational axis or symmetrical axis, wherein the inlet channel (10) flows through the boundary wall (8) into the nebulization chamber (2) in such a way that the carrier gas in the nebulization chamber (2) is guided on a spiral flow path and exposed to an imparted swirl, wherein, in the nebulization chamber (2), a baffle plate (36) is arranged opposite the active-liquid container (4), the outlet channel (12) is formed by an outlet pipe (28) which is guided in its longitudinal direction by a cover flange (30) of the nebulization chamber (2), and the baffle plate (36) is attached to this at the end of the end and at a distance from the outlet opening (38) of the outlet pipe (28) via a number of carrier bars (40) so that, by shifting the outlet pipe (28) in the cover flange (30), the height of the positioning of the baffle plate (36) above the active liquid can also be changed.

2. The aerosol generator (1) according to Claim 1, the inlet channel (10) of which is connected on the input side to a pump unit (42) by means of which the inflow rate and / or velocity of the carrier gas flowing into the nebulization chamber (2) is adjustable.

3. The aerosol generator (1) according to any one of Claims 1 to 2, wherein the outlet pipe (28) can be moved by twisting in the cover flange (30).

4. The aerosol generator (1) according to Claim 3, wherein, in the area of the penetration through the cover flange (30), the outlet pipe (28) is provided with an external thread (32) which interacts with a corresponding internal thread in the cover flange (30), and, via this thread combination, the outlet pipe (28) is screwed into the cover flange (30) so that a twisting of the outlet pipe (28) in the cover flange (30) is transposed into a shift in the longitudinal direction.

5. The aerosol generator (1) according to any one of the Claims 1 to 4, wherein the boundary wall (8) and / or the cover flange (30) of the nebulization chamber (2) comprises a number of refill openings (46) for the active liquid.