Surface Acoustic Wave Nebulization for 1-5 μm Lung Drug Delivery
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Solution Overview
Problem
Current nebulizer systems have limitations in delivering drugs to the lung, with only 70%-80% of the dose reaching the target, and are unable to nebulize suspensions and liquids with high viscosity and surface tension, while also producing broad droplet size distributions that are suboptimal for respiratory disease treatment.
Innovation Solution
A device using surface acoustic waves (SAWs) to generate nebulized droplets by interacting with a liquid in an array of cavities on a SAW transmission surface, controlling droplet size distribution to achieve greater than 95% delivery of active drug to the lung, suitable for treating respiratory diseases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional nebulizer systems are used, then they can deliver medication to the lung, but only 70%-80% of the dose reaches the target and droplet size distribution is broad
Solution Approach 1:
The invention segments the liquid into discrete droplets of controlled size by passing it through a mesh screen with specific aperture dimensions. The mesh acts as a physical segmentation tool that divides the continuous liquid stream into individual droplets, enabling precise control over droplet size distribution and improving delivery efficiency to the lung target.
Solution Approach 2:
The invention changes physical parameters including mesh aperture size, vibration frequency, and liquid flow rate to optimize droplet size distribution. By adjusting these parameters, the system achieves a narrow droplet size distribution centered in the respiratory range (1-5 μm), thereby improving both manufacturing precision and drug delivery reliability.
2Manufacturing precision
If surface acoustic waves are used to nebulize liquid, then droplet size distribution can be controlled tightly, but the device complexity increases
Solution Approach 1:
The invention replaces complex mechanical nebulization mechanisms with surface acoustic wave (SAW) technology. The SAW transducer generates ultrasonic vibrations that interact with the liquid-mesh system to produce controlled droplet formation, eliminating the need for complex mechanical moving parts while achieving tight droplet size distribution.
Solution Approach 2:
The invention utilizes the phase transition from liquid to aerosol droplets through acoustic energy input. Surface acoustic waves provide the energy necessary to overcome surface tension and transform the liquid phase into dispersed droplet phase, achieving precise size control without complex mechanical systems.
3Length of moving object
If droplet size is reduced below 1 μm, then smaller droplets can be formed, but they are trapped in the upper respiratory tract or throat
Solution Approach 1:
The invention optimizes the droplet size parameter within the specific range of 1-5 μm based on respiratory physiology. This parameter selection ensures droplets are small enough to bypass upper respiratory trapping but large enough to deposit effectively in the lung parenchyma, maximizing delivery reliability to the target organ.
Solution Approach 2:
The invention incorporates feedback mechanisms to monitor and adjust droplet size distribution in real-time. By measuring the actual droplet size output and comparing it to the target range, the system can adjust operating parameters to maintain optimal droplet dimensions for lung delivery, preventing both trapping and ineffective deposition.
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 SAW-based nebulizer system provides a tight distribution of droplet sizes between 1-5 μm, improving treatment outcomes by enhancing the delivery of therapeutic agents to the lungs, particularly for conditions like cystic fibrosis and asthma, with the potential to reduce healthcare costs and improve clinical outcomes.
Implementation Method 1
a surface acoustic wave (SAW) transducer adapted to generate and propagate SAWs along the SAW transmission surface
Implementation Method 2
SAWs propagating along the SAW transmission surface interact with the liquid in the cavities to produce nebulised droplets
Implementation Method 3
an array of cavities opening at the SAW transmission surface for containing a liquid
Data Source
Figure 1A~1B
Figure 2(a)~2(d)
Figure 3
AI summary
A device is disclosed for the preparation of nebulised droplets, for inhalation. The device has: a surface acoustic wave (SAW) transmission surface; a SAW transducer adapted to generate and propagate SAWs along the SAW transmission surface; and an array of cavities opening at the SAW transmission surface for containing a liquid. In operation, SAWs propagating along the SAW transmission surface interact with the liquid in the cavities to produce nebulised droplets of the liquid. Operation of the device results in a nebulised plume of droplets of average diameter in the range 1-5μm.