Dry Powder Inhaler Winding Wheel Indexing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inhalers with peelable blister packages face challenges in accurately indexing the blister package for each actuation, leading to inconsistent delivery of dry powder medicaments, which can result in either incomplete or excessive dosing, posing safety risks due to the difficulty in ensuring proper opening of the blister pocket.
Innovation Solution
The inhaler design incorporates a winding wheel with polyoxymethylene resilient wings composed of three parts, which balances the force of attraction on the lid sheet, ensuring consistent indexing of the blister package with each actuation, and a gear mechanism that indexes and peels the blister package properly, along with a specific ratio of manifold to mouthpiece outlet cross-sections to achieve effective airflow and pressure drop for precise medicament delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a peelable blister package is used in the inhaler, then the blister pocket can be opened completely to enable sufficient airflow and effective inhalation, but the blister package cannot be indexed properly to the same extent in each actuation, leading to inconsistent dosing
Solution Approach 1:
The winding wheel is divided into multiple resilient wings (at least two, preferably three or more) that are spaced around the circumference. Each resilient wing independently engages with the blister package during rotation, distributing the indexing action across multiple contact points to ensure consistent and complete opening of the blister pocket with each actuation.
Solution Approach 2:
The resilient wings are made of polyoxymethylene material with specific mechanical properties that allow them to flex and apply controlled force during the indexing process. The elasticity and recovery characteristics of this material enable the winding wheel to consistently index the blister package to the required extent without excessive force or incomplete engagement.
2Reliability
If the blister package is indexed more than the required extent, then complete opening is achieved, but more than one blister pocket may be opened, leading to excessive dosing
Solution Approach 1:
The resilient wings are designed to provide just sufficient indexing action to open the blister pocket completely without excessive force that would advance multiple pockets. The partial action of each resilient wing is coordinated to achieve the minimum required opening while preventing over-indexing and accidental opening of adjacent pockets.
Solution Approach 2:
The gear mechanism provides mechanical feedback that limits the rotation of the winding wheel to the precise angle required for single-pocket opening. This feedback control ensures that the blister package is indexed exactly to the required extent, preventing both incomplete opening and excessive opening that would lead to dosing errors.
3Productivity
If the manifold outlet cross-section is large, then airflow is improved, but pressure drop is reduced below the required 4 kPa for effective inhalation
Solution Approach 1:
The cross-sectional area ratio between the manifold outlet and mouthpiece outlet is precisely controlled within the range of 1:10 to 1:50. This parameter optimization ensures that sufficient airflow reaches the mouthpiece while maintaining a pressure drop higher than 4 kPa, which is necessary for effective inhalation and medicament delivery to the lungs.
Solution Approach 2:
The airflow pathway is designed as a composite system combining the manifold outlet and mouthpiece outlet with specific geometric relationships. The tapered channel connecting these outlets creates a progressive flow transition that maintains pressure differential while ensuring adequate airflow, effectively resolving the contradiction between flow rate and pressure drop.
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
This design ensures consistent and accurate delivery of the required dose of dry powder medicament with each actuation, minimizing the risk of incomplete or excessive dosing, and effectively delivers the medicament to the lungs by maintaining a pressure drop higher than 4 kPa, ensuring efficient inhalation and preventing residual medicament accumulation.
Implementation Method 1
a winding wheel with polyoxymethylene resilient wings composed of three parts, which balances the force of attraction on the lid sheet
Implementation Method 2
maintaining a pressure drop higher than 4 kPa, ensuring efficient inhalation and preventing residual medicament accumulation
Data Source
AI summary
The present invention relates to an inhaler which is appropriate for delivery of medicament in dry powder form used in respiratory diseases, particularly in asthma and chronic obstructive pulmonary disease (COPD). In addition, the present invention relates to an inhaler which includes a blister package appropriate for carrying the medicament in dry powder form and used to realize an effective inhalation.