Vented Ocular Fluid Delivery for Precise Preservative-Free Dosing
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Solution Overview
Problem
Current methods for delivering pharmaceutical fluids to the eye surface, such as using drop bottles, result in inaccurate application, excessive fluid volume, and loss due to blinking, with potential microbial contamination risks.
Innovation Solution
A device that delivers a precise micro-dose of fluid (<10uL) within a blink time (~100ms) using optical aiming and an electromagnetic transducer to eject the fluid at controlled velocities (1-10 m/s) through a nozzle aperture (200-600 µm) with a venting system to prevent microbial ingress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a drop bottle is used to deliver pharmaceutical fluids to the eye, then the delivery method is simple, but the application accuracy is poor and fluid volume is excessive
Solution Approach 1:
The device segments the fluid delivery process into precise micro-doses (5-10 μL) delivered through a controlled aperture, rather than delivering undifferentiated drops from a bottle. This segmentation enables accurate dosing while maintaining relatively simple device operation.
Solution Approach 2:
The invention replaces the simple mechanical gravity-based drop delivery system with a more sophisticated system incorporating an electromagnetic transducer to generate acoustic waves that eject fluid through a nozzle. This substitution enables precise control over fluid ejection timing and velocity.
2Quantity of substance
If a large volume drop is delivered, then the fluid reservoir capacity is sufficient, but the tear film cannot absorb the excess fluid
Solution Approach 1:
The invention changes the key parameter of fluid volume from typical drop sizes (50 μL) to micro-doses (5-10 μL). This parameter change ensures the delivered volume matches the tear film's absorption capacity, improving reliability while maintaining adequate dosing.
3Speed
If the fluid is delivered slowly, then the patient can aim accurately, but the blinking reflex blocks the fluid before it reaches the cornea
Solution Approach 1:
The device uses periodic acoustic waves generated by an electromagnetic transducer to eject fluid in controlled pulses. This periodic action delivers fluid rapidly (within 100ms) before the blink reflex occurs, while the aiming mechanism allows patients to position the device correctly before activation.
4Stress or pressure
If the aperture is opened continuously to allow air ingress for pressure balancing, then the pressure equilibrium is maintained, but microbial contamination occurs
Solution Approach 1:
The device incorporates a pre-sterilized ampoule that is sealed until use. The aperture remains closed during storage and handling, and is only opened at the moment of fluid ejection. This preliminary preparation ensures pressure balancing can occur without microbial contamination risk.
Solution Approach 2:
The invention introduces a filter as an intermediary element between the external environment and the fluid reservoir. This filter allows air to pass through for pressure balancing while blocking microbial ingress, resolving the contradiction between pressure equilibrium and contamination prevention.
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
Ensures precise delivery to the cornea, reduces fluid loss, and maintains sterility by preventing microbial contamination, while optimizing fluid ejection parameters for patient comfort and safety.
Implementation Method 1
an electromagnetic transducer to eject the fluid at controlled velocities (1-10 m/s) through a nozzle aperture
Implementation Method 2
as liquid is ejected, air should be introduced to replace the ejected volume and thereby balance the pressure (venting)
Data Source
Figure 1~2
Figure 3A
Figure 3B~3C
AI summary
A device for delivery of a precise amount of pharmaceutical fluid to the eye is provided. The device includes an ampoule for storing a liquid and an aperture through which the liquid is discharged. The device further includes a vibrating membrane that includes a needle which protrudes from the membrane and extends to the aperture to form a needle valve. The needle valve provides hermetic closure of the aperture to enable preservative-free storage of the pharmaceutical fluid in the device. The system further includes an electromagnetic transducer to shift the membrane back and forth in order to discharge liquid through the nozzle. Finally, the system further includes a vent to permit air to enter the ampoule as fluid is ejected from the ampoule. Preferably this vent includes a filter to prevent ingress of microbes or other contaminants to the ampoule.