Gas-Powered Powder Dispensing Device with Angled Duct
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing dry powder inhalers, particularly passive ones, face challenges in achieving consistent de-agglomeration and high inhalable fractions due to variability in breathing flow rates, leading to inefficient delivery of powder drugs to specific lung regions.
Innovation Solution
An active, gas-powered dispensing device with a non-circular duct design featuring angled and forked portions to generate high shear forces for effective de-agglomeration, combined with a flat cross-section and impinging powder jets to produce a slow, fine spray plume with optimal characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a passive inhaler is used where powder is inhaled by the patient without additional energy source, then the device complexity is reduced, but the inhalable fraction becomes highly variable depending on patient breathing flow rate
Solution Approach 1:
The patient's own breathing effort serves as the power source for the inhaler, eliminating the need for batteries, compressors, or other active components. The breathing actuation mechanism uses the patient's inhalation flow to drive the valve and deliver the dose, making the system self-servicing while maintaining consistent performance across different patients.
Solution Approach 2:
The valve design incorporates flow-dependent parameters that automatically adjust the delivery characteristics based on the patient's breathing flow rate. The valve opening area, spring constant, and chamber geometry are optimized to maintain consistent de-agglomeration and aerosol generation across a range of inhalation flows, transforming the variable input into a consistent output.
2Manufacturing precision
If the duct is designed with angled and forked portions to generate high shear forces, then the de-agglomeration effectiveness is improved, but the device complexity increases
Solution Approach 1:
The duct is divided into distinct functional sections: a straight section for initial powder entry, angled sections for generating shear forces and de-agglomeration, and a forked section for distributing the aerosol flow. Each segment performs a specific function, allowing complex de-agglomeration through a series of simple geometric transitions rather than a single complex mechanism.
Solution Approach 2:
The duct incorporates smooth curved transitions and angled portions instead of sharp corners, creating controlled turbulence and shear zones that effectively de-agglomerate particles. The curved geometry guides the flow smoothly while generating the necessary mechanical forces, avoiding dead zones and facilitating complete powder utilization.
3Reliability
If a high fraction of small particles is generated for alveolar delivery, then the delivery efficiency to lung is improved, but the propagation velocity of the spray plume increases
Solution Approach 1:
The duct geometry creates different flow conditions in different regions: high shear zones for de-agglomeration, transition zones for aerosol formation, and a low-velocity outlet region for controlled plume delivery. The outlet is designed to maintain low propagation velocity while preserving the fine particle size distribution generated in the upstream sections.
Solution Approach 2:
The forked duct configuration distributes the aerosol flow into multiple parallel streams, reducing the velocity in each individual stream while maintaining the overall delivery rate. This dimensional approach allows the plume to spread and slow down without sacrificing the fraction of small particles that reach the alveoli.
4Duration of action of moving object
If the spray generation duration is extended, then the inhalation time for patient is improved, but the gas volume required increases
Solution Approach 1:
The valve and spring system is designed with dynamic characteristics that maintain a steady, controlled flow over an extended period. The spring constant and valve opening area are optimized to provide a prolonged aerosol generation at consistent velocity, allowing the patient adequate time to inhale the full dose without requiring excessive gas volume.
Solution Approach 2:
The duct and valve geometry are optimized to achieve effective de-agglomeration and aerosol generation with a moderate, controlled gas flow rather than a large volume. The extended duration is achieved by maintaining efficient particle-gas interaction throughout the entire gas pulse, ensuring complete powder utilization without excess gas consumption.
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 device achieves improved de-agglomeration and higher inhalable fractions with finer particle sizes, reducing powder retention and ensuring consistent delivery to targeted lung regions with lower gas volume and pressure requirements.
Implementation Method 1
the duct is angled by at least about 90 degrees at a diversion portion and/or is diverted into two at least substantially opposite directions at a fork portion so that the powder is impacted on to and/or sheared by a solid surface (impaction or deflection surface) for powder de-agglomeration
Implementation Method 2
the powder is impacted on to and/or sheared by a solid surface (impaction or deflection surface) for powder de-agglomeration. The impaction of the powder particles on the surface or wall results in a surprisingly good de-agglomeration of the powder particles
Data Source
AI summary
A dispensing device for dispensing powder as a spray is disclosed. The dispensing device comprises a duct through which the powder is dispensable by gas pressure for de-agglomerating the powder. The duct is angled by at least about 90 degrees at a diversion portion and/or diverted into two opposite directions at a fork portion so that the powder is impacted on to or sheared by a solid surface for powder de-agglomeration.