Metered-Dose Inhaler Actuator Orifice Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Metered-dose inhalers (MDIs) face limitations in orifice design flexibility due to manufacturing constraints, which restrict the variety of shapes that can be achieved, and struggle to effectively reduce the proportion of non-respirable particles or droplets dispensed, impacting aerosol performance.
Innovation Solution
A metered-dose inhaler actuator with a housing design that allows for a greater variety of orifice shapes by aligning the longitudinal axis of the orifice with the valve stem receptacle, incorporating air inlet openings to establish airflow patterns that entrain respirable particles and impaction of non-respirable particles within the actuator, thereby enhancing fine particle delivery and reducing deposition in the oro-pharyngeal region.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional molding procedures with pins are used to form the orifice, then manufacturing simplicity is maintained, but orifice design flexibility is limited to cylindrical shapes or shapes flaring towards the mouthpiece opening
Solution Approach 1:
The patent inverts the traditional approach by aligning the orifice longitudinal axis with the valve stem axis (0° angle), whereas traditionally the orifice was oriented at 90°-110° to the valve stem axis. This inversion enables greater design flexibility including tapering shapes toward the mouthpiece opening while maintaining manufacturability through conventional molding techniques.
Solution Approach 2:
The patent introduces a new dimensional configuration by changing the angular orientation of the orifice relative to the valve stem from the traditional 90°-110° to 0° alignment. This dimensional change in spatial arrangement enables novel orifice geometries such as tapering shapes that were not feasible with the traditional orthogonal arrangement.
2Productivity
If the orifice is oriented at 90° to 110° from the valve stem direction as in traditional designs, then aerosol propulsion towards the mouthpiece is achieved, but the proportion of non-respirable particles dispensed is reduced
Solution Approach 1:
The patent applies local quality by creating a specific airflow environment through strategically positioned air inlet openings that generate turbulent flow patterns in the expansion chamber. This localized turbulent flow enhances atomization quality and reduces non-respirable particle formation at the orifice exit, while maintaining overall aerosol delivery efficiency.
Solution Approach 2:
The patent changes the orifice orientation parameter from 90°-110° to 0° alignment with the valve stem axis, and introduces air inlet openings with specific dimensions and positions. These parameter changes modify the airflow dynamics and atomization characteristics, resulting in reduced non-respirable particle proportion while maintaining or improving aerosol delivery efficiency.
3Productivity
If air inlet openings are added to establish airflow patterns for particle separation, then fine particle delivery is enhanced, but device complexity increases
Solution Approach 1:
The air inlet openings serve multiple functions simultaneously: they provide structural support as part of the actuator housing, enable turbulent airflow for enhanced atomization, facilitate particle separation through impaction, and maintain pressure balance. This multi-functionality enhances fine particle delivery without proportionally increasing device complexity.
Solution Approach 2:
The actuator design uses the patient's own inhalation flow to generate the turbulent airflow patterns needed for particle separation and atomization enhancement. The air inlet openings are positioned to utilize the natural breathing flow, eliminating the need for additional active components or external power sources, thus enhancing fine particle delivery without significant complexity increase.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design achieves a higher fraction of fine particles and improved aerosol performance by aligning the orifice axis with the valve stem receptacle and utilizing air inlet openings to enhance airflow, resulting in reduced non-respirable particle deposition and comparable or superior performance to traditional designs.
Implementation Method 1
incorporating air inlet openings to establish airflow patterns that entrain respirable particles
Implementation Method 2
impaction of non-respirable particles within the actuator
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
Metered-dose inhaler actuator, metered-dose inhaler and method of using the same An actuator (11) for a metered-dose inhaler (1) is provided. The actuator (11) com- prises a housing having a mouthpiece portion (13) and a canister receiving portion (12) configured to receive a canister (2). The actuator (11) further comprises a member (14) disposed within the housing and defining a valve stem receptacle (15) con- figured to receive a valve stem (3) of the canister (2). An orifice (16) is formed in the member (14), which is in fluid communication with the valve stem receptacle (15) and extending to a face (19) of the member (14) opposite to the valve stem receptacle (15). A longitudinal axis (18) of the orifice (16) is aligned with a longitudinal axis (17) 15 of the valve stem receptacle (15). At least one air inlet opening (20) is provided in an outer shell of the housing so as to be spaced from an opening (21) for receiving the canister (2) and a mouthpiece opening (22).