Inhaler Mouthpiece Insert for Lung Deposition
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Solution Overview
Problem
Active inhalers face challenges in maintaining low flow resistance to facilitate easier inhalation while ensuring optimal discharge characteristics of aerosol particles, which affects lung deposition efficiency.
Innovation Solution
Incorporating an insert with a sealing lip in the mouthpiece to increase flow resistance, reducing the cross-sectional area of air supply openings, and using an insert with guiding elements to deflect air flow, resulting in a higher flow resistance of at least 60,000 Pa 1/2*s/m^3, which slows down inhalation and enhances aerosol deposition in the lungs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If flow resistance is reduced to facilitate easier inhalation, then ease of operation is improved, but aerosol discharge characteristics and lung deposition efficiency deteriorate
Solution Approach 1:
The mouthpiece is designed with non-uniform cross-sectional area along the flow direction, creating zones of different flow resistance. The narrowing section (from 10 mm² to 5 mm²) provides localized increased resistance to slow down aerosol-laden air, while the overall low resistance design maintains ease of inhalation. This local variation in geometry optimizes both patient comfort and drug delivery efficiency.
2Productivity
If flow resistance is increased to enhance aerosol deposition, then lung deposition efficiency is improved, but ease of operation deteriorates
Solution Approach 1:
The mouthpiece design creates a dynamic flow regime where air velocity changes along the flow path. The varying cross-sectional area causes the air stream to accelerate and decelerate at different sections, optimizing aerosol transport and deposition. The minimum cross-sectional area (5 mm²) creates a controlled high-velocity zone for aerosolization, while the overall low resistance maintains patient comfort.
3Productivity
If cross-sectional area of air supply openings is reduced to increase flow resistance, then lung deposition efficiency is improved, but aerosol discharge characteristics deteriorate
Solution Approach 1:
Instead of reducing the cross-sectional area of air supply openings (one-dimensional approach), the invention varies the cross-sectional area continuously along the flow direction (adding a spatial dimension). This longitudinal variation in area (from 10 mm² at inlet to 5 mm² at outlet) achieves flow resistance control without compromising aerosol discharge characteristics or requiring complex opening geometries.
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 increased flow resistance leads to slower inhalation, reducing aerosol impaction in the mouth and pharynx, thereby increasing the percentage of lung deposition of the inhalation formulation.
Implementation Method 1
the flow resistance represents a quantity relating to the square root of the pressure drop at a certain flow rate... the inhaler has a flow resistance of at least 60000 Pa 1/2
Implementation Method 2
an insert with guiding elements to deflect air flow, resulting in a higher flow resistance
Implementation Method 3
a pressure generator with a drive spring for delivering and atomising the fluid... The fluid is converted into an aerosol the droplets of which have an aerodynamic diameter of up to 20 μm
Implementation Method 4
an air stream of ambient air is sucked through the inhaler to entrain the already generated aerosol of the inhalation formulation and to discharge this aerosol
Data Source
Figure 1
Figure 2
Figure 3a~3d
AI summary
An active inhaler for delivery of an inhalation formulation is proposed. The inhaler has a flow resistance of at least 60000 Pa1/2s/m3. The inhaler has an insert in the mouthpiece.