A method of airway modification for a capsule-based dry powder inhaler

Abstract

The application discloses a capsule type dry powder inhaler airway improvement method and relates to the technical field of dry powder inhalers, which comprises a capsule rotating bin and an air inlet channel 2 in communication with the capsule rotating bin, wherein the air inlet channel 2 is a wedge-shaped air inlet; the width of the inlet end of the wedge-shaped air inlet is h, the width of the outlet end close to the capsule rotating bin is h*, and the ratio coefficient R = h* / h is satisfied; the inhalation airflow enters the capsule rotating bin through the wedge-shaped air inlet to generate a pneumatic force, and the pneumatic force acting on both ends of the capsule forms a torque for driving the capsule to rotate around the axis of the capsule; the application solves the problems of low air suction power conversion rate, insufficient capsule rotation and low drug powder depolymerization efficiency in the prior art.

Description

Technical Field

[0001] This invention relates to the technical field of dry powder inhalers, specifically to a method for improving the airway of a capsule-type dry powder inhaler. Background Technology

[0002] Dry powder inhalers are the core devices for targeted drug delivery to the lungs. Single-capsule dry powder inhalers use symmetrical tangential air inlets to create a vortex that drives the capsule to rotate, causing the drug powder inside the capsule to deagglomerate and form an inhalable aerosol.

[0003] The air intake channel of existing inhalers starts from a straight section of constant cross-section at the inlet end (e.g. Figure 1 As shown by the red lines on the left and right sides), the capsule gradually expands into a funnel-shaped semi-open structure at the exit end (as shown by the red lines on the left and right sides). Figure 1 As shown by the green dashed line, R=1.8).

[0004] The side with airflow aligning with the capsule's rotation direction maintains a straight line shape, tangent to the capsule's circular outline, creating a smooth transition. The side with airflow opposite to the capsule's rotation direction seamlessly connects to the capsule's circular boundary with a large-radius rounded corner, exhibiting a highly integrated, continuous curved surface transition. This design avoids abrupt breaks or steps between the airflow channel and the capsule body, achieving a smooth, streamlined geometric transition. However, this semi-open, flared design, with its circular transition boundary, easily generates airflow opposite to the capsule's rotation direction. Some inhaled energy is dissipated, and the overall airflow velocity is insufficient to generate adequate aerodynamic force at the capsule tip. This results in slow capsule rotation, incomplete drug release, lower collision frequency and energy between the capsule and the capsule wall, difficulty in deagglomerating drug powder agglomerates, and a lower fine particle fraction (FPF).

[0005] Meanwhile, current inhalers generally use a single, fixed air intake channel, which cannot adjust the airflow lever arm and torque according to the patient's inspiratory capacity. Existing fixed air intake structures cannot balance capsule drive torque and breathing resistance as needed, thus failing to proactively adapt to different populations and achieve optimal delivery. By introducing an adjustable modular design, a non-fixed air intake channel design can be created. This allows for adjustment of the optimal inspiratory channel shape based on the inspiratory capacity of different populations, fully utilizing inspiratory power, enhancing drug release and depolymerization processes, and optimizing drug delivery efficiency. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a method for improving the airway of a capsule-type dry powder inhaler.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0008] This invention provides a capsule-type dry powder inhaler, comprising:

[0009] a capsule rotation chamber; and

[0010] an air inlet channel in communication with the capsule rotation chamber, wherein the air inlet channel is a wedge-shaped air inlet;

[0011] the width of the inlet end of the wedge-shaped air inlet is h, the width of the outlet end close to the capsule rotation chamber is h*, and the proportionality coefficient R=h* / h is satisfied;

[0012] The inhaled airflow passes through the wedge-shaped air inlet and enters the capsule rotation chamber to generate aerodynamic force, and the aerodynamic force acting on both ends of the capsule forms a torque that drives the capsule to rotate around its own axis.

[0013] As a preferred technical solution of the present invention, the proportionality coefficient R is 0.1≤R≤0.4, so that the wedge-shaped air inlet is in a converging shape;

[0014] Alternatively, the proportionality coefficient R is 0.4<R≤1.0;

[0015] Alternatively, the proportionality coefficient R is 1.0<R≤2.0, so that the wedge-shaped air inlet is in a diverging shape.

[0016] As a preferred technical solution of the present invention, the two side boundaries of the wedge-shaped air inlet are smooth-transitioning continuous curve contours;

[0017] The continuous curve contour includes an involute of a circle, a parabola, a cubic spline curve, a Bezier curve, a clothoid, an Euler spiral, or a combination thereof.

[0018] As a preferred technical solution of the present invention, the continuous curve contour is a double involute contour, so that both side boundaries of the wedge-shaped air inlet are involutes of a circle.

[0019] As a preferred technical solution of the present invention, the inner boundary of the wedge-shaped air inlet is merged with the outer wall surface of the circular capsule rotation chamber, and only the outer boundary is retained to form a spiral wedge-shaped air inlet.

[0020] As a preferred technical solution of the present invention, the inhaler further comprises an inhaler main body, wherein the wedge-shaped air inlet is arranged on a replaceable functional module, and the replaceable functional module is mounted on the inhaler main body through a quick-release structure;

[0021] Wherein, the quick-release structure is a buckle, a thread or a magnetic attraction structure.

[0022] The present invention discloses a method for improving an air passage of a capsule-type dry powder inhaler, and the method comprises the following steps:

[0023] setting the air inlet channel entering the capsule rotation chamber as the wedge-shaped air inlet, and setting the width of the inlet end as h and the width of the outlet end as h*;

[0024] Define and adjust the proportional coefficient R=h* / h to control the convergence or divergence degree of the wedge-shaped air inlet, so as to regulate the balance between airflow characteristics and the breathing resistance of the device, thereby improving the rotation torque of the capsule and the deagglomeration efficiency of the medicinal powder.

[0025] As a preferred technical solution of the present invention, the step of regulating the balance between airflow characteristics and the breathing resistance of the device specifically comprises:

[0026] When the proportional coefficient is adjusted to 0.1≤R≤0.4, the wedge-shaped air inlet is in a convergent shape;

[0027] Alternatively, when the proportional coefficient is adjusted to 0.4<R≤1.0, the wedge-shaped air inlet is in a convergent shape or a constant cross-section shape.

[0028] As a preferred technical solution of the present invention, the method further comprises an airflow guiding optimization step:

[0029] Both the inner boundary and the outer boundary of the wedge-shaped air inlet are set as involute curves of a circle to form a double-involute profile; alternatively, the inner boundary of the wedge-shaped air inlet is integrated with the outer wall surface of the capsule rotation bin to form a spiral wedge-shaped air inlet, and the airflow impact angle is controlled through geometric constraints, so that the airflow acts vertically on the end of the capsule.

[0030] As a preferred technical solution of the present invention, the method further comprises the step of establishing test feedback correlation:

[0031] Obtain the rotation speed of the capsule under different inspiratory flow rates, the fine particle fraction FPF measured by an impactor, and the breathing resistance of the device;

[0032] Establish a correlation relationship between the proportional coefficient R and the rotation speed, the fine particle fraction FPF and the breathing resistance, and select the corresponding R value of the proportional coefficient for the target population based on the correlation relationship.

[0033] The beneficial effects of the present invention are as follows:

[0034] 1. Under the working condition that the patient inhales to form an inspiratory airflow, the present invention adopts a structure in which the capsule rotation bin is matched with the wedge-shaped air inlet, and sets and adjusts the inlet end width h, the outlet end width h* and the proportional coefficient R of the wedge-shaped air inlet, so as to control the convergence or divergence degree of the wedge-shaped air inlet and regulate the airflow characteristics and the breathing resistance of the device, which solves the problems of low inspiratory power conversion rate, insufficient capsule rotation and low medicinal powder deagglomeration efficiency in the prior art, and finally achieves the effects of improving the rotation torque of the capsule and increasing the fine particle fraction FPF of particles with an aerodynamic diameter of ≤5μm.

[0035] 2. This invention optimizes the airflow guidance structure by setting the two sides of the wedge-shaped air inlet to a smooth transition continuous curve profile, or forming a spiral wedge-shaped air inlet. This reduces airflow separation and turbulence loss, and allows the airflow to act perpendicularly on the end of the capsule. It solves the problems of low airflow guidance accuracy and poor energy conversion efficiency in the existing air inlet channel 2, and ultimately achieves the effect of stabilizing the capsule rotation state and improving the uniformity of drug powder deagglomeration. Attached Figure Description

[0036] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0037] Figure 1 This is a schematic diagram of the air intake channel of an inhaler in the prior art;

[0038] Figure 2 This is a schematic diagram of the overall structure of the capsule-type dry powder inhaler of the present invention;

[0039] Figure 3 A perspective view of the airflow inlet design for the capsule-type dry powder inhaler of the present invention;

[0040] Figure 4 A plan view of the airflow inlet design for the capsule-type dry powder inhaler of the present invention;

[0041] Figure 5 This is a plan view of the airflow inlet design of one type of air intake channel 2 according to the present invention;

[0042] Figure 6 This is a plan view of the airflow inlet design of the wedge-shaped air intake channel 2 with double involute curves of the present invention.

[0043] Figure 7 A plan view of the airflow inlet design of the spiral-shaped wedge-shaped air intake channel 2 of the present invention;

[0044] Figure 8 This is a schematic diagram of the structure of the air intake channel 2 with different proportionality coefficients R according to the present invention;

[0045] Figure 9 This is a schematic diagram of the FPF generated by the intake passage 2 with different proportionality coefficients R according to the present invention.

[0046] Figure 10 This is a schematic diagram of the capsule rotation speed generated by the air intake channel 2 with different proportional coefficients R according to the present invention.

[0047] Figure 11 This is a schematic diagram showing the flow rate and device breathing resistance values ​​measured under different proportionality coefficients R according to the present invention.

[0048] Figure 12This is a schematic diagram comparing the particle-particle collision energy and the particle-wall collision energy under different scaling factors R according to the present invention.

[0049] Figure 13 Box plots showing the collision energy distribution under different scaling factors R according to the present invention.

[0050] In the diagram: 1. Capsule rotating chamber; 2. Air intake channel 2; 3. Capsule storage chamber; 4. Suction nozzle; 5. Grille. Detailed Implementation

[0051] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this application, and not all embodiments. The components of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0052] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this application, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0053] like Figures 2-7 As shown, a capsule-type dry powder inhaler includes a capsule rotating chamber 1 and an air inlet channel 2 communicating with the capsule rotating chamber 1. The air inlet channel 2 is configured as a wedge-shaped air inlet. This wedge-shaped air inlet extends along the airflow direction, with its end furthest from the capsule rotating chamber 1 being the inlet end and its end closest to the capsule rotating chamber 1 being the outlet end. The width of the inlet end is denoted as h, and the width of the outlet end is denoted as h*. The inlet end width h and the outlet end width h* satisfy a proportionality coefficient R = h* / h.

[0054] During use, the patient actively inhales through nozzle 4, and outside air enters the capsule rotating chamber 1 through the wedge-shaped air inlet. As the inhaled airflow flows within the wedge-shaped air inlet, the airflow velocity and pressure distribution change due to the change in cross-sectional dimensions. After entering the capsule rotating chamber 1, the airflow acts on both ends of the capsule placed inside the chamber. This airflow force generates a torque at both ends of the capsule, driving the capsule to rotate around its own axis.

[0055] Under the action of this torque, the capsule continuously rotates within the capsule rotation chamber 1. During the rotation process, the medicinal powder inside the capsule is released through the opening at the end of the capsule into the capsule rotation chamber 1 under the action of centrifugal force, and mixes with the airflow to form an inhalable aerosol. Meanwhile, the capsule collides with the inner wall of the capsule rotation chamber 1 and the structure of the grid 5 during rotation, which further promotes the depolymerization of the medicinal powder agglomerates.

[0056] The structure of the wedge-shaped air inlet enables the airflow to obtain a specific acceleration or guiding effect before entering the capsule rotation chamber 1, so that the rotational motion of the capsule can be driven without adding additional moving parts.

[0057] Further, on the basis of the above structure, the present invention further limits the numerical range of the proportionality coefficient R to adapt to different usage scenarios and patients' respiratory capabilities.

[0058] (1) Convergent wedge-shaped air inlet

[0059] When the proportionality coefficient R is set to 0.1≤R≤0.4, the wedge-shaped air inlet is convergent, that is, the width h* at the outlet end is smaller than the width h at the inlet end. Under this configuration, the airflow is compressed in the channel and the flow velocity increases. After the accelerated airflow enters the capsule rotation chamber 1, the aerodynamic force component acting on both ends of the capsule increases. At the same time, the position of the airflow action point is closer to the end of the capsule, and the effective force arm increases correspondingly, so that the torque driving the capsule to rotate is improved.

[0060] This convergent design is suitable for situations where strong capsule rotation power and high-dose delivery are required, and the patient has relatively sufficient inspiratory capacity. According to Figures 8 to 10 the experimental data shown, when R=0.2 or 0.4, the capsule rotation speed and the fine particle fraction (FPF, that is, the fine particle fraction is the mass percentage of particles with an aerodynamic diameter ≤5μm in the total delivered dose) are both improved compared with when R=1.8 (i.e., the original design).

[0061] (2) Intermediate range wedge-shaped air inlet

[0062] When the proportionality coefficient R is set to 0.4<R≤1.0, the wedge-shaped air inlet is convergent or of equal cross-section. Within this range, a balance is achieved between torque enhancement and respiratory resistance increase. Experimental data show (see Figure 9 , Figure 11 ) that this R value range is suitable for most adults and some elderly patients, which can not only provide sufficient capsule rotation effect, but also will not cause excessively high respiratory resistance when the patient inhales.

[0063] (3) Divergent wedge-shaped air inlet

[0064] When the proportionality coefficient R is set to satisfy 1.0<R≤2.0, the wedge-shaped air inlet is in a divergent form, that is, the width h* at the outlet end is greater than the width h at the inlet end. Under this configuration, the pressure of the air flow in the channel decreases, and the flow resistance is reduced. A patient can obtain a high inhalation flow rate with low breathing resistance during use. This divergent design is suitable for patients with weak inhalation capacity. Although the torque gain is relatively limited, the overall breathing resistance is low, which improves the inhalation comfort and compliance of the patient, while ensuring sufficient inhalation volume and delivered dose.

[0065] The above three R value ranges can be selected according to the respiratory physiological parameters of the target population. An operator or medical care worker can determine the appropriate R value range by measuring or evaluating the inhalation flow capacity of a patient, and then select an inhaler of the corresponding specification or replace the corresponding air intake module.

[0066] Experimental data (see Figure 9 , Figure 10 ) show that, under the same inhalation volume, compared with the prior art (i.e., the design with R=1.8), the wedge-shaped air inlets with different R values have the capsule rotation speed increased by about 26% (corresponding to R=1) to 78% (corresponding to R=0.2), and the corresponding fine particle fraction (FPF) also obtains an absolute increase of 3.4% to 10.8% (a 6.5% to 20.8% increase relative to the original design).

[0067] Further, as shown in Figure 6 , the two side boundaries of the wedge-shaped air inlet are set as smoothly transitioning continuous curved profiles. The continuous curved profiles replace the straight boundaries of the wedge-shaped channel. Compared with the wedge-shaped through hole, the smooth curved profile can guide the air flow to gradually turn in the channel, reducing flow separation and local turbulence loss.

[0068] Specifically, the continuous curved profile may adopt one or a combination of more of the following geometric curves:

[0069] involute of a circle; parabola; cubic spline curve; Bezier curve; clothoid (also called Euler spiral).

[0070] Taking the embodiment shown in Figure 6 as an example, both side boundaries are involutes of a circle. The curves extend smoothly in a bent manner from the inlet end to the outlet end. When the air flow flows through the involute profile, the direction of the air flow is gradually deflected, and finally enters the capsule rotation bin 1 at an angle more perpendicular to the axis of the capsule and impacts the end of the capsule.

[0071] This change in the incident angle increases the effective component of the aerodynamic force in the direction perpendicular to the force arm, thereby generating a larger driving torque under the same inhalation flow condition. At the same time, the smooth curved profile reduces eddy currents and energy dissipation of the air flow at the inlet corner, so that the air flow energy is more efficiently converted into mechanical energy for capsule rotation.

[0072] Figure 7 The spiral wedge-shaped air inlet structure, which integrates the inner boundary with the outer wall of the circular capsule rotating chamber 1, is further demonstrated. In this embodiment, the improved airflow guidance can be achieved by independently employing smooth curved profiles for both side boundaries.

[0073] Furthermore, the continuous curve profile is a double involute profile, that is, the two sides of the wedge-shaped air inlet are both involute curves of circles.

[0074] In this embodiment, the two side boundaries are formed by unfolding from their respective base circles. The two involute curves bend in opposite directions, jointly defining a wedge-shaped channel whose width gradually changes along the airflow direction.

[0075] Specifically, such as Figure 6 As shown, both the outer and inner boundaries of the wedge-shaped air inlet are circular involutes. The outer involute curves from the inlet end to the outlet end, and the inner involute similarly curves from the inlet end to the outlet end. The distance between the starting points (i.e., the inlet end) of the two involutes is h, and the distance between their ending points (i.e., the outlet end, where it connects with the capsule rotating chamber 1) is h*. Due to the geometric characteristics of the involute, the channel width from the inlet end to the outlet end changes monotonically, and the rate of change is continuously differentiable, with no inflection points or sharp angles.

[0076] Compared to wedge-shaped channels or single-curve boundaries, the double involute profile has the following structural features: as the airflow flows within the channel, the guiding direction of the airflow from the side walls changes continuously and smoothly. The airflow moves along the involute tangent, and at the channel exit, the airflow direction forms a specific incident angle with the tangent direction of the capsule rotating chamber 1. Experimental measurements show that this incident angle increases the effective aerodynamic component of the airflow acting on the capsule end.

[0077] Furthermore, the double involute profile eliminates the geometric abrupt changes in the side walls of the wedge-shaped inlet. In a wedge-shaped channel, there is an angle between the airflow direction and the wall at the inlet end, which easily leads to flow separation and local vortices, resulting in energy loss. However, in the double involute profile, the airflow flows along the involute tangent from the inlet end, and the wall is always tangent to the airflow direction, thereby reducing the flow separation area.

[0078] In terms of manufacturing, the wedge-shaped air inlet with a double involute profile can be processed using injection molding. The involute of the circle can be defined by parametric equations, and the mold cavity is machined accordingly. The radius of the base circle can be selected according to the overall dimensions of the inhaler, typically ranging from 2 mm to 10 mm. The radius of the base circle and the unfolded length of the involute together determine the rate of change of the length and width of the wedge-shaped air inlet.

[0079] In one embodiment of the invention, the two side boundaries of the double involute profile use the same base circle parameter, so that the channel centerline remains straight. In another embodiment, the two side boundaries can use different base circle parameters, so that the channel centerline exhibits a certain curvature to adapt to different layout requirements of the capsule rotating chamber 1.

[0080] Furthermore, the inner boundary of the wedge-shaped air inlet merges with the outer wall of the circular capsule rotating chamber 1, retaining only the outer boundary, to form a spiral wedge-shaped air inlet.

[0081] Specifically, in a conventional capsule rotating chamber 1 structure, the rotating chamber is a cylindrical or near-cylindrical cavity with an arc-shaped outer wall. In this embodiment, the inner boundary of the wedge-shaped air inlet is directly set to coincide with the arc-shaped outer wall, meaning the inner boundary becomes part of the wall of the capsule rotating chamber 1. Thus, the wedge-shaped air inlet no longer has an independent inner wall; instead, its inner guide surface is naturally formed by the outer wall of the capsule rotating chamber 1.

[0082] The outer boundary is retained as an independent curve. This outer boundary adopts a smooth curved profile, which can be an involute of a circle, a parabola, a cubic spline curve, a Bézier curve, a cycloid, an Euler spiral, or a combination thereof. The outer boundary and the outer wall of the capsule rotating chamber 1 together define the wedge-shaped air intake channel 2.

[0083] From the perspective of airflow, when the airflow enters from the inlet, its inner flow travels entirely along the arc-shaped wall of the capsule rotating chamber 1, while the outer flow travels along the outer boundary curve. Because the inner wall is arc-shaped, the airflow naturally changes direction as it flows along it, ultimately entering the capsule rotating chamber 1 in a near-tangential direction. The shape of the outer boundary curve further constrains the width variation and degree of turning of the airflow.

[0084] The geometry of this spiral wedge-shaped air inlet allows for precise control of the angle between the airflow direction and the tangent direction at the capsule tip when the airflow enters the rotating capsule chamber 1. By adjusting the parameters of the outer boundary curve (such as the base circle radius and unfolding angle), the incident angle of the airflow impacting the capsule tip can be made to a predetermined value. Experiments show that the torque acting on the capsule is maximized when the airflow direction is nearly perpendicular to the capsule tip surface.

[0085] refer to Figure 7Compared to the double involute profile (where both sides are independent curves), the spiral wedge-shaped air inlet of this embodiment integrates the inner boundary with the capsule rotating chamber 1, reducing the number of independent wall surfaces in the air intake channel 2. This structure has the following advantages: First, it simplifies the mold structure because the inner boundary no longer needs an independent forming surface; second, it reduces abrupt changes in airflow at the junction of the channel and the rotating chamber because the inner wall surface is a continuous arc surface; third, it achieves a longer airflow guiding distance within a limited space, allowing for more thorough adjustment of the airflow direction.

[0086] In actual products, the outer boundary curve of the spiral wedge-shaped air inlet can be designed into different shapes as needed. Taking an involute as an example, the center of the base circle of the outer involute can coincide with or not coincide with the center of the rotating capsule 1. When they coincide, the outer involute and the inner arc form a channel width variation with equal or variable pitch. When they do not coincide, the channel width exhibits an asymmetrical variation along the circumference.

[0087] In terms of manufacturing, the inhaler with a spiral wedge-shaped air inlet can be integrally injection molded. The arc-shaped wall surface and outer boundary curve of the capsule rotating chamber 1 are formed simultaneously through the mold cavity. This structure does not increase the number of additional parts and is suitable for mass production.

[0088] Figure 7 In the illustrated embodiment, the outer boundary is an involute circle, and the inner boundary is the arcuate wall of the capsule rotating chamber 1. The area between the two forms a wedge-shaped air intake channel 2. The inlet width h is the radial distance from the starting point of the outer boundary to the inner arcuate wall, and the outlet width h* is the radial distance from the ending point of the outer boundary to the inner arcuate wall. The definition of the proportionality coefficient R = h* / h remains unchanged.

[0089] Furthermore, the inhaler also includes an inhaler body. The wedge-shaped air inlet is not directly fixed to the inhaler body, but is located on a separate, replaceable functional module. This replaceable functional module is installed on the inhaler body via a quick-release mechanism.

[0090] The inhaler body includes basic structures such as a capsule rotating chamber 1, a mouthpiece 4, a grille 5, a capsule storage chamber 3, and a bottom cover (not shown in the figure). A replaceable functional module is independent of the inhaler body and has the aforementioned wedge-shaped air inlet channel inside. One end face or side of this module has an opening; when the module is installed on the inhaler body, this opening aligns with the air inlet on the inhaler body, allowing outside air to enter the capsule rotating chamber 1 through the wedge-shaped air inlet of the module.

[0091] Specifically, the quick-release structure can be a snap-on, threaded, or magnetic structure.

[0092] The snap-fit structure is provided with a hook and a slot on the mating surfaces of the module and the inhaler body respectively. When the module is pushed or screwed into a predetermined position, the hook elastically deforms and snaps into the slot, producing a "click" sound to indicate that the installation is in place. During disassembly, press or toggle the unlock button to release the hook from the slot, and the module can be taken out. The snap-fit structure is suitable for application scenarios that require frequent replacement and have moderate positioning accuracy requirements.

[0093] The threaded structure is provided with an external thread on the outer surface of the module and an internal thread at the corresponding interface of the inhaler body. After the module is rotated for several turns, it is fixed to the body through thread engagement. The threaded structure has reliable connection and good sealing performance, and is suitable for scenarios where accidental falling off needs to be prevented. In addition, the threaded structure can provide precise axial positioning, so that the outlet of the module and the air inlet of the body are accurately aligned.

[0094] The magnetic attraction structure has permanent magnets or magnetically conductive bodies embedded on the docking surfaces of the module and the inhaler body respectively. The module is attached to the body by magnetic attraction. The magnetic attraction structure is the most convenient to install and disassemble, no rotation or pressing is required, and automatic alignment and adsorption can be achieved by directly approaching. This structure is suitable for scenarios with low requirements for installation force, and can avoid mechanical wear caused by repeated disassembly and assembly.

[0095] The above three quick-release structures are all prior art, and their specific structures will not be repeated here.

[0096] By arranging the replaceable functional modules, the present invention supports the following usage modes:

[0097] The same inhaler body can be equipped with a plurality of wedge-shaped air inlet modules with different R values. Medical staff or patients can select and install a module with an appropriate R value according to the test result of the patient's inspiratory capacity. For example, patients with strong inspiratory capacity or requiring high-dose delivery select a module with 0.1≤R≤0.4, and patients with weak inspiratory capacity select a module with 1.0<R≤2.0.

[0098] Wedge-shaped air inlets of different geometric shapes (such as double involute wedge shape and spiral wedge shape) can also be made into different modules respectively. Patients or doctors can replace modules of different shapes according to clinical needs.

[0099] In the production stage of the product, a series of modules with standardized interfaces can be manufactured, while the inhaler body adopts a unified design. This reduces inventory management costs and improves the adaptability range of the product.

[0100] The modular design also facilitates cleaning or replacement. When the air inlet channel 2 of a certain module is blocked or contaminated, only the module needs to be replaced, and the entire inhaler does not need to be discarded.

[0101] In one embodiment of the invention, the quick-release structure is a snap-fit ​​structure. The outline shape of the module matches the mounting groove on the inhaler body, and an air inlet is provided at the bottom of the mounting groove. After the module is inserted into the mounting groove, the snap-fit ​​automatically locks, and the wedge-shaped air inlet outlet of the module aligns with the air inlet at the bottom of the mounting groove. The outer surface of the module is provided with anti-slip texture for easy gripping and insertion / removal.

[0102] In another embodiment of the invention, the quick-release structure is a threaded structure. The module is cylindrical, with threads on its outer surface, and the inhaler body has a circular hole with internal threads. After the module is screwed into the circular hole, its end face forms a seal with the bottom of the circular hole. The number of thread turns is 1.5 to 3 turns to ensure quick tightening.

[0103] In another embodiment of the invention, the quick-release structure is a magnetic structure. Magnets are respectively positioned on the module and the inhaler body, with the magnetic force set such that they will not detach due to vibration or slight contact during normal use, but can be easily pulled apart by hand. Positioning posts and positioning holes are also provided between the module and the body to ensure precise circumferential and radial alignment.

[0104] The three quick-release structures described above can be used individually or in combination. For example, a combination of clips and magnets can provide double security while maintaining the convenience of quick release.

[0105] It should be noted that the replaceable functional module itself includes a wedge-shaped air inlet. The module is made of the same material as the inhaler body, both being medical-grade plastics (such as polypropylene, polycarbonate, acrylonitrile-butadiene-styrene copolymer, etc.). The module is manufactured using the same injection molding process as the inhaler body. The module's small size facilitates mass production and replacement.

[0106] The present invention also provides a method for improving the airway of a capsule-type dry powder inhaler, the method comprising the following steps:

[0107] Step 1: Set the air intake channel 2 that enters the capsule rotating chamber 1 as a wedge-shaped air intake, and set the width of the inlet end to h and the width of the outlet end to h*.

[0108] During the manufacturing or design phase of the inhaler, the position and size of the capsule rotating chamber 1 are first determined. An air intake channel 2 connecting to the outside is opened on the side wall of the capsule rotating chamber 1. The air intake channel 2 is processed into a wedge shape with a cross-sectional dimension that gradually changes along the airflow direction. The wedge-shaped air intake has two end faces: the end away from the capsule rotating chamber 1 is the inlet end, and its width is denoted as h; the end closer to the capsule rotating chamber 1 is the outlet end, and its width is denoted as h*. The values ​​of the inlet end width h and the outlet end width h* are initially set according to the breathing capacity of the target user group and the overall size of the inhaler. The measurement direction of h and h* is perpendicular to the main airflow direction and parallel to or at a predetermined angle to the axial direction of the capsule.

[0109] Step 2: Define and adjust the proportional coefficient R=h* / h to control the degree of convergence or expansion of the wedge-shaped air inlet, thereby regulating the balance between airflow characteristics and device breathing resistance, and thus improving the capsule rotation torque and powder deagglomeration efficiency.

[0110] After setting h and h*, calculate the proportionality coefficient R = h* / h. The value of R directly determines the geometry of the wedge-shaped air inlet: when R < 1, the width of the outlet end is smaller than the width of the inlet end, and the air inlet is converging; when R = 1, the widths of the inlet and outlet are equal, and the air inlet is a channel with a constant cross-section; when R > 1, the width of the outlet end is greater than the width of the inlet end, and the air inlet is expanding.

[0111] By adjusting the R value, the rate of change of airflow velocity, pressure distribution, and outflow direction within the wedge-shaped channel can be altered. Specifically, the smaller the R value (the greater the degree of convergence), the more significantly the airflow is compressed within the channel, resulting in a higher outlet velocity and stronger momentum and directionality of the airflow impacting the capsule tip, thereby increasing the torque driving the capsule's rotation. However, a higher degree of convergence also leads to increased resistance as the airflow passes through the channel, requiring the patient to exert greater inspiratory effort to achieve the same flow rate. Conversely, the larger the R value (the greater the degree of expansion), the less obstruction the channel provides to the airflow, reducing respiratory resistance, but the relative gain of the airflow's driving torque on the capsule decreases.

[0112] The core of this method lies in achieving the desired balance between the two mutually restrictive performance parameters, "capsule rotation torque" and "device breathing resistance," by adjusting the R value.

[0113] For patients with strong inspiratory capacity, a smaller R value can be selected to pursue higher drug depolymerization efficiency; for patients with weak inspiratory capacity (such as children, the elderly, and patients with chronic obstructive pulmonary disease), a larger R value can be selected to reduce respiratory resistance and ensure that sufficient airflow can still be obtained at low inspiratory energy so that the capsule can start to rotate and release the drug powder.

[0114] As the rotational speed of the capsule increases within the capsule rotating chamber 1, the collision frequency and energy between the capsule and the chamber wall and grid 5 increase. Under the action of centrifugal force and collision, the powder inside the capsule is released more fully from the opening at the end of the capsule, and the powder agglomerates deagglomerate into inhalable particles with a particle size of 1-5 micrometers in the airflow and collision.

[0115] This method does not rely on changing the drug formulation or adding additional moving parts; performance optimization can be achieved simply by adjusting the geometric parameters of the air intake channel 2. It has the advantages of low implementation cost and wide applicability.

[0116] Further, when an operator or designer adjusts the proportionality coefficient R to the range of 0.1≤R≤0.4, the wedge-shaped air inlet presents a distinct convergent shape, that is, the width h* at the outlet end is much smaller than the width h at the inlet end. Under this geometric configuration, the intake air flow undergoes significant acceleration during the process of flowing through the wedge-shaped air inlet.

[0117] When the operator or designer adjusts the proportionality coefficient R to the range of 0.4<R≤1.0, the wedge-shaped air inlet is made to be convergent or of constant cross-section, that is, the width h* at the outlet end is greater than 0.4 times the width at the inlet end and less than or equal to the width at the inlet end.

[0118] When 0.1≤R≤0.4, according to the principle of fluid continuity, under the assumption of incompressible flow, the mass flow rate through the passage remains constant, and the reduction in cross-sectional area leads to an increase in flow velocity. Specifically for the present method, the air flow flows in from the position with the inlet end width h, and during the process of flowing toward the position with the outlet end width h*, the cross-sectional area of the passage gradually decreases, and the air flow velocity gradually increases. Near the outlet end, the air flow reaches the highest velocity in the entire passage.

[0119] While for R=0.4~1.0, the convergence degree of the passage is small or the passage is of constant cross-section, and the acceleration effect of the air flow is correspondingly weakened.

[0120] This acceleration effect brings about the following two mechanical results:

[0121] First, the effective aerodynamic force component F acting on both ends of the capsule is increased. When the air flow impacts the end of the capsule at a relatively high velocity, the dynamic pressure generated by the air flow on the capsule surface increases. The dynamic pressure is proportional to the square of the flow velocity, so a small increase in the flow velocity will lead to a significant increase in the impact force. The component of this impact force in the direction perpendicular to the axis of the capsule is the effective aerodynamic force component F, and the increase of F directly contributes to the torque that drives the capsule to rotate.

[0122] Second, the action point of the air flow is made to approach the end of the capsule to increase the effective force arm d. Under the guidance of the convergent wedge-shaped air inlet, the jet direction of the high-speed air flow is narrowed, and its centerline is more concentrated toward the end region of the capsule. Compared with the traditional constant-cross-section or divergent air inlet, the action point of the air flow further moves from the middle part or the vicinity of the end of the capsule to the extreme end of the capsule. Since the force arm d is defined as the perpendicular distance from the rotation axis (usually the central axis of the capsule) to the line of action of the air flow force, when the action point moves toward the end of the capsule, the value of d increases, and in the case that F remains unchanged or increases, the increase of d further enhances the torque M=F×d.

[0123] Combining the above two effects, when 0.1≤R≤0.4, the torque M is significantly improved. The experimental data (refer to Figure 10This indicates that within this R value range, the capsule rotational speed (RPM) is significantly higher than when R is close to 1. The higher capsule rotational speed increases the collision frequency and energy between the capsule and the capsule wall, promoting the release and deagglomeration of the drug powder.

[0124] It should be noted that the range of 0.1 ≤ R ≤ 0.4 corresponds to higher respiratory resistance. This setting is suitable for patients with sufficient inspiratory reserve (such as young adults and patients with non-obstructive airway diseases), or in clinical scenarios requiring high-dose drug delivery. When selecting this R value range, healthcare professionals should confirm that the patient's peak inspiratory flow rate can overcome the device resistance and generate sufficient flow.

[0125] In one specific embodiment of this method, such as Figure 11 As shown, a wedge-shaped air inlet module with R=0.2 was manufactured by injection molding and installed on the inhaler body. In vitro tests were conducted on healthy volunteers. The inhalation flow rate measured at a pressure difference of 4 kPa was 81.64 L / min, falling within the medium resistance range (50~90 L / min). The capsule rotation speed reached 4590 RPM. At R=0.2, the FPF was 62.776%, an absolute increase of approximately 10.8 percentage points and a relative increase of approximately 20.8% compared to R=1.8 and FPF=51.984%. This indicates that within an acceptable resistance range, this method effectively improves torque and powder deagglomeration efficiency.

[0126] Furthermore, the airflow guidance optimization step specifically includes the following two optional implementation schemes:

[0127] Option 1: Double involute profile

[0128] The inner and outer boundaries of the wedge-shaped air inlet are both set as involute curves of circles, forming a double involute profile. This step is achieved as follows: First, two base circles are determined, the positions and radii of which are based on the center of the capsule rotating chamber 1 and the layout of the air intake channel 2. Then, the inner and outer involutes are generated respectively, so that the two involutes extend from the inlet end to the outlet end, and the distance between them gradually changes from h to h*.

[0129] With the adoption of a double involute profile, when the airflow flows in the channel, both side walls are smooth and have continuously varying curvature. The airflow flows along the tangent of the involute. At the channel outlet, the airflow direction forms a predetermined angle with the tangent of the capsule rotating chamber 1. This angle allows the airflow to impact the end of the capsule more directly, rather than the side of the capsule. Since the effective aerodynamic component F depends on the angle between the airflow direction and the capsule axis, the F value reaches its maximum when the airflow acts more perpendicularly on the capsule end face.

[0130] Compared to a wedge-shaped air inlet, the double involute profile eliminates flow separation and vortex losses at wall corners, enabling airflow energy to be converted into the rotational kinetic energy of the capsule more efficiently.

[0131] Option 2: Spiral wedge-shaped air inlet

[0132] The inner boundary of the wedge-shaped air inlet is integrated with the outer wall of the capsule rotating chamber 1 to form a spiral wedge-shaped air inlet. This step involves eliminating the separate inner wall, so that the inner side of the wedge-shaped air inlet channel 2 is directly formed by the arc-shaped outer wall of the capsule rotating chamber 1 itself. The outer boundary remains an independent curve (which can be an involute, parabola, cubic spline, Bézier curve, cycloid, Euler spiral, or a combination thereof).

[0133] Through this geometric constraint, the airflow always flows along the arc-shaped wall on its inner side before entering the capsule rotating chamber 1. The arc-shaped wall naturally deflects the airflow direction gradually, changing it from radial flow to tangential flow. The shape of the outer boundary curve further controls the rate of change of the channel width and the degree of airflow tightening. When the airflow reaches the outlet end, the angle between its flow direction and the tangential direction at the end of the capsule is precisely defined.

[0134] The key to this method is to control the airflow impact angle through geometric constraints, so that the airflow acts vertically on the end of the capsule. Vertical impact means that the direction of the airflow coincides with the normal direction of the capsule end face. At this time, all the aerodynamic force is converted into pressure perpendicular to the capsule end face. The component of this pressure in the direction perpendicular to the capsule axis is the effective driving force. Compared with oblique impact, vertical impact generates the largest torque.

[0135] In one specific embodiment, an involute of a circle is used as the outer boundary. The base circle of the involute is concentric with the capsule rotating chamber 1. By adjusting the development angle of the involute, the tangent of the involute at the outlet end coincides with the tangent direction of the capsule rotating chamber 1. At this time, the airflow enters the capsule rotating chamber 1 in a pure tangential direction and directly impacts the edge of the capsule end located in the chamber, forming the maximum torque.

[0136] This airflow guidance optimization step can be implemented independently of the R-value adjustment step, or it can be implemented in combination with the R-value adjustment step. For example, a target R-value (such as R=0.6) can be selected first, and then, while keeping the R-value unchanged, the boundary shape can be changed from a straight line to a double involute or a spiral wedge to further improve the airflow impact angle.

[0137] The common technical effect of the two approaches is to improve the effective utilization of airflow and enhance capsule rotation performance without increasing the patient's inspiratory burden.

[0138] Furthermore, this step is used to quantitatively determine the relationship between the proportionality coefficient R and the key performance parameters of the inhaler, and to select the corresponding R value for the target population based on this relationship. This embodiment enables the airway improvement method to move from qualitative design to quantitative optimization, possessing repeatability and verifiability.

[0139] The steps for establishing test feedback associations specifically include the following sub-steps:

[0140] Sub-step 1: Obtain the rotational speed of the capsule under different inhalation flow rates.

[0141] A high-speed camera system was used to film the movement of the capsule inside the capsule rotating chamber 1. During the test, the inhaler was fixed on a breathing simulator, and the inspiratory flow rate was set to 60 L / min.

[0142] With a flow rate of 60 L / min, the airflow is started and the capsule rotation process is filmed. The filming frequency is set to 800 frames / second, and each recording time is no less than 10 seconds. Select video frames in the middle of the recording time (e.g., from the 3rd to the 7th second), read the angular displacement of the capsule frame by frame or at intervals, calculate the number of rotations per unit time, and obtain the capsule rotation speed, which is usually expressed in revolutions per minute (RPM).

[0143] For wedge-shaped air inlets with different R values ​​(e.g., R = 0.2, 0.4, 0.6, 0.8, 1.0), the above test was repeated to obtain a set of data on "R value - inspiratory flow rate - capsule rotation speed". Experimental data (see...) Figure 10 The data shows that, at the same inspiratory flow rate, the smaller the R value, the higher the capsule rotation speed; the larger the R value, the lower the capsule rotation speed. In addition, the inspiratory flow rate-capsule rotation speed data corresponding to R=1.8 (i.e., the original design) is also provided.

[0144] Sub-step 2: Obtain the fine particle fraction (FPF) measured by the impactor.

[0145] The next-generation impactor (NGI) was used for testing according to the pharmacopoeia method (General Rules and Guidelines, Part IV, 2015 edition of the Chinese Pharmacopoeia), with a test flow rate set to 60 L / min. A certain dose of drug capsule was placed in the inhaler, the airflow was activated, and drug particles deposited in each stage of the impactor were collected. The mass of each stage of the drug was weighed or determined by high-performance liquid chromatography (HPLC). The total mass of drug particles with an aerodynamic diameter of 5 μm or less was calculated and divided by the total mass of drug delivered from the inhaler to obtain the fine particle fraction (FPF), expressed as a percentage. For wedge-shaped inlets with different R values, at least three repeated measurements were performed, and the average value was taken.

[0146] The final data for FPF and capsule rotation speed at different R values ​​are shown in Table 1 below:

[0147]

[0148] Table 1. FPF and capsule rotation speed at different R values

[0149] Specifically, when R=0.2, the FPF is 62.776% and the capsule rotation speed is 4590 RPM; when R=1.8, the FPF is 51.984% and the capsule rotation speed is 2580 RPM.

[0150] Compared to R=1.8, the FPF of R=0.2 increased by approximately 10.8 percentage points in absolute terms and approximately 20.8% in relative terms; the capsule rotation speed increased by approximately 2010 RPM in absolute terms and approximately 78% in relative terms.

[0151] This data shows that a decrease in the R value simultaneously increases capsule rotation speed and FPF, validating the optimizing effect of the wedge-shaped air inlet on drug delivery performance.

[0152] Sub-step 3: Obtain the breathing resistance of the device.

[0153] Tests were conducted using a Dose Uniformity Sampling Apparatus (DUSA tube) in conjunction with a vacuum pump and flow meter. The tests were conducted according to the United States Pharmacopeia. <601> Alternatively, the method described in European Pharmacopoeia 2.9.18 may be used, applying a pressure of -4 kPa at the outlet of the device and measuring the steady-state volumetric flow rate through the device.

[0154] Repeat the above test for wedge-shaped air inlets with different R values. Experimental data (see...) Figure 11 The results showed that as the R value decreased, the inhaled flow rate decreased and the breathing resistance increased, but the overall change was relatively gradual. The resistance corresponding to all tested R values ​​(0.2~1.8) fell within the low or medium resistance range (i.e., the flow rate was greater than 50 L / min at -4 kPa).

[0155] Sub-step four: Establish the correlation between the proportionality coefficient R and rotational speed, fine particle fraction (FPF), and respiratory resistance.

[0156] The data obtained from the above tests are summarized, and statistical analysis (such as regression analysis and curve fitting) is used to establish mathematical or tabular relationships between R-values ​​and various performance parameters. For example, functional forms can be established: RPM=f1(R), FPF=f2(R), Resistance=f3(R). These relationships are presented in the form of charts or empirical formulas.

[0157] Sub-step 5: Select the corresponding proportional coefficient R value for the target population based on the aforementioned correlation.

[0158] First, determine the typical inspiratory flow rate range or recommended upper limit of respiratory resistance for the target population (e.g., children, adults, elderly patients, patients with chronic obstructive pulmonary disease). For example, for elderly people or children with weak inspiratory capacity, prioritize inhalers with a flow rate greater than 70 L / min at -4 kPa (i.e., low respiratory resistance) (see reference). Figure 11 As can be seen, with the minimum R=0.2 shown in the figure, the inhalation flow rate is 81.64 L / min, which is greater than 70 L / min. Therefore, the technical means of the present invention meets the requirements.

[0159] Refer to the relationships established in step four to find the range of R values ​​that satisfy the flow condition. Further select the R value within this range that maximizes the FPF. Figure 9 and Figure 11 For target populations that need to balance low resistance and high FPF, a value of R in the range of 0.4 to 1.0 can be selected (such as R = 0.6 or 0.8).

[0160] For patients with strong inspiratory capacity (such as young and middle-aged asthmatic patients), a high FPF is preferred, while moderate respiratory resistance is acceptable. In this case, correlations can be consulted, and an R value within the range of 0.2 to 0.4 can be selected.

[0161] Furthermore, this test feedback correlation step can also be used for batch-to-batch quality control of inhaler products. By periodically sampling and checking the R-value and corresponding FPF of the products, consistency in product performance is ensured. During the R&D phase, this method is used to screen for the optimal R-value and the optimal inlet geometry.

[0162] Through the above-mentioned test feedback correlation steps, this method realizes evidence-based selection of R value, which elevates the airway improvement of capsule dry powder inhalers from experience-based design to data-driven precise control, making it suitable for the development trend of personalized medicine and precision drug delivery.

[0163] To further explain the influence mechanism of the proportionality coefficient R on the deagglomeration efficiency of the drug powder, this embodiment uses the CFD-DEM numerical simulation method to analyze the variation law of particle-particle collision energy and particle-wall collision energy under different R values. The simulation conditions are set as follows: gas flow rate of 60 L / min and particle size distribution of drug powder of 1~5 μm. The results are as follows. Figure 12 , Figure 13 As shown.

[0164] Figure 12 The values ​​of particle-particle collision energy and particle-wall collision energy are shown for different R values. As the R value decreases from 1.8 to 0.4, both collision energies show an increasing trend. When R=0.4, both particle-particle collision energy and particle-wall collision energy reach their maximum values.

[0165] Figure 13 The statistical distribution of collision energy under various design parameters is shown in the form of a box plot. The box represents the 25% to 75% quantile range, the middle horizontal line is the 50% quantile value, and the upper and lower lines correspond to the 10% and 90% quantile values, respectively. As can be seen from the figure, the overall level of collision energy when R=0.4 is significantly higher than that when R=1.8, and the data distribution is more concentrated.

[0166] The increase in collision energy indicates that the fine particle fraction (FPF) increases as the R value decreases: higher collision energy promotes the deagglomeration of drug powder agglomerates, allowing more drug particles to disperse into the inhalable particle size range.

[0167] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A capsule-type dry powder inhaler, characterized in that, comprising: a capsule rotation bin (1); and an air inlet channel 2 (2) in communication with the capsule rotation bin (1), wherein the air inlet channel 2 (2) is a wedge-shaped air inlet; the width of the inlet end of the wedge-shaped air inlet is h, the width of the outlet end close to the capsule rotation bin (1) is h*, and the proportionality coefficient R=h* / h is satisfied; The inhaled airflow flows through the wedge-shaped air inlet into the capsule rotation bin (1) to generate aerodynamic force, and the aerodynamic force acting on both ends of the capsule forms a torque that drives the capsule to rotate around its own axis.

2. The capsule-type dry powder inhaler according to claim 1, characterized in that, The proportionality coefficient R is 0.1≤R≤0.4, so that the wedge-shaped air inlet is in a converging shape; alternatively, the proportionality coefficient R is 0.4<R≤1.0; alternatively, the proportionality coefficient R is 1.0<R≤2.0, so that the wedge-shaped air inlet is in a diverging shape.

3. The capsule-type dry powder inhaler according to claim 1, characterized in that, The boundaries on both sides of the wedge-shaped air inlet are smooth and transitional continuous curve profiles; The continuous curve profile comprises an involute of a circle, a parabola, a cubic spline curve, a Bezier curve, a clothoid, an Euler spiral, or a combination thereof.

4. The capsule-type dry powder inhaler according to claim 1, characterized in that, The continuous curve profile is a double-involute profile, so that both side boundaries of the wedge-shaped air inlet are involutes of a circle.

5. The capsule-type dry powder inhaler according to claim 1, characterized in that, The inner boundary of the wedge-shaped air inlet is merged with the outer wall surface of the circular capsule rotation bin (1), and only the outer boundary is retained to form a spiral wedge-shaped air inlet.

6. The capsule-type dry powder inhaler according to claim 1, characterized in that, Further comprising an inhaler main body, wherein the wedge-shaped air inlet is arranged on a replaceable functional module, and the replaceable functional module is mounted on the inhaler main body through a quick-release structure; wherein the quick-release structure is a buckle, a thread or a magnetic attraction structure.

7. A method for improving the airway of a capsule-type dry powder inhaler, characterized in that, A method applied to the capsule-type dry powder inhaler according to any one of claims 1 to 6, the method comprising the following steps: setting the air inlet channel 2 (2) entering the capsule rotation bin (1) as the wedge-shaped air inlet, and setting the width of the inlet end as h and the width of the outlet end as h*; defining and adjusting the proportionality coefficient R=h* / h to control the convergence or divergence degree of the wedge-shaped air inlet, so as to regulate and control the balance between airflow characteristics and the breathing resistance of the device, thereby improving the capsule rotation torque and the powder deagglomeration efficiency.

8. The method for improving the airway of a capsule-type dry powder inhaler according to claim 7, characterized in that, The step of regulating and controlling the balance between the airflow characteristics and the breathing resistance of the device specifically comprises: when the proportionality coefficient is adjusted to 0.1≤R≤0.4, making the wedge-shaped air inlet in a converging shape; alternatively, when the proportionality coefficient is adjusted to 0.4<R≤1.0, making the wedge-shaped air inlet in a converging shape or a constant cross-section shape.

9. A method for improving the airway of a capsule-type dry powder inhaler according to claim 7, characterized in that, The method further comprises an airflow guiding optimization step: arranging both the inner boundary and the outer boundary of the wedge-shaped air inlet as involutes of a circle to form a double-involute profile; or merging the inner boundary of the wedge-shaped air inlet with the outer wall surface of the capsule rotation bin (1) to form a spiral wedge-shaped air inlet, and controlling the airflow impact angle through geometric constraints, so that the airflow acts vertically on the end of the capsule.

10. A method for improving the airway of a capsule-type dry powder inhaler according to claim 7, characterized in that, The method further comprises the step of establishing a test feedback correlation: acquiring the rotation speed of the capsule at different inspiratory flow rates, the fine particle fraction FPF measured by an impactor, and the breathing resistance of the device; Establish the correlation between the proportionality coefficient R and the rotational speed, the fine particle fraction (FPF), and the respiratory resistance, and select the corresponding proportionality coefficient R value for the target population based on the correlation.

Images