Liquid Droplet Dispenser Actuation Pump Seal Opening
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Solution Overview
Problem
Existing devices for delivering a metered dose of liquid medication in droplet form to the eye often face challenges in ensuring precise delivery and minimizing hydraulic energy, particularly when dealing with preservative-free medications.
Innovation Solution
A dispenser system that includes a housing with an outlet orifice, a tip seal, and both dosing and actuation pumps, where the actuation pump operates at higher pressure than the dosing pump, providing a hydraulic opening force to the tip seal to deliver droplets with low hydraulic energy, and uses a common liquid for both pumps to minimize contamination and optimize droplet formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a tip seal is used to seal the outlet orifice, then droplet formation is improved and contamination is minimized, but higher opening pressure is required to open the seal
Solution Approach 1:
A separate actuation pump is introduced as an intermediary component to provide the high pressure needed to open the tip seal, while the dosing pump operates at low pressure for droplet delivery. This mediator pump temporarily supplies hydraulic opening force only when needed to separate the seal from the orifice.
Solution Approach 2:
The pumping function is segmented into two separate pumps: a dosing pump for low-pressure liquid delivery and an actuation pump for high-pressure seal opening. This segmentation allows each pump to be optimized for its specific function without compromise.
2Object-affected harmful factors
If a common liquid is used for both dosing and actuation pumps, then contamination risk is minimized, but the actuation pump requires priming with medication
Solution Approach 1:
The actuation pump is pre-filled (primed) with the medication before use. This preliminary action ensures that when the pump operates, it delivers the medication through the same pathway as the dosing pump, eliminating contamination risk while accepting the added priming step as a necessary preparatory measure.
3Force
If the actuation pump operates at higher pressure than the dosing pump, then the tip seal can be opened effectively, but hydraulic energy for droplet delivery increases
Solution Approach 1:
The actuation pump operates periodically only when seal opening is needed, rather than continuously. This periodic high-pressure operation is followed by low-pressure dosing operation, reducing overall energy consumption while maintaining effective seal opening capability when required.
Solution Approach 2:
The delivery process is segmented into two phases: a high-pressure actuation phase for seal opening and a low-pressure dosing phase for droplet delivery. This temporal segmentation ensures high hydraulic opening force when needed while minimizing hydraulic energy consumption during the actual droplet delivery.
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 system ensures precise and controlled delivery of metered doses with low hydraulic energy, effectively managing droplet formation and minimizing contamination risks, particularly suitable for preservative-free medications.
Implementation Method 1
an actuation pump configured to provide a hydraulic opening force to the tip seal for opening of the outlet orifice
Implementation Method 2
a tip seal, biased against the housing to seal the outlet orifice
Implementation Method 3
a dosing pump for pumping a liquid to the outlet nozzle
Data Source
AI summary
A dispenser for the delivery of a droplet of a liquid comprises a housing which defines an outlet orifice, a tip seal, biased against the housing to seal the outlet orifice, and a dosing pump for pumping a liquid to the outlet nozzle. The dispenser further comprises an actuation pump configured to provide a hydraulic opening force to the tip seal for opening of the outlet orifice. Preferably the actuation pump is configured to operate at a higher pressure than the dosing pump.