Precision Dispensing Device for Small Volume Allergy Testing
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Solution Overview
Problem
Existing prefilled syringes face challenges in accurately metering small volumes of fluid due to difficulties in precisely dispensing material from the dispensing opening, leading to inefficiencies in multiple allergy tests.
Innovation Solution
A dispenser system comprising a dispenser body and plunger, which includes a syringe mounting region, a nozzle portion with a measuring cavity, and a dispenser plunger that operates independently of the syringe plunger to ensure precise dispensing of a predetermined volume by forming a seal and preventing fluid bypass, allowing for accurate incremental dispensing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a standard prefilled syringe is used to dispense small volumes of fluid, then the syringe can hold and store the fluid, but it is very difficult to accurately meter the amount of fluid being dispensed from the dispensing opening
Solution Approach 1:
The device segments the dispensing process into two independent stages: (1) filling the measuring cavity through the syringe plunger, and (2) dispensing the measured volume through the dispenser plunger. This segmentation allows each stage to be optimized independently, achieving both ease of operation and measurement precision.
Solution Approach 2:
The measuring cavity acts as an intermediary component between the syringe and the external environment. It receives fluid from the syringe and transfers a precise predetermined volume to the outside, enabling accurate metering without requiring the user to directly control small volume dispensing.
2Measurement precision
If the dispenser plunger is actuated independently of the syringe plunger, then precise dispensing of predetermined volume is achieved, but the device complexity increases
Solution Approach 1:
The device uses two separate plungers (syringe plunger and dispenser plunger) that operate independently. The syringe plunger fills the measuring cavity, while the dispenser plunger dispenses the measured volume. This segmentation enables precise predetermined volume dispensing by decoupling the filling and dispensing functions.
Solution Approach 2:
The dispensing function is extracted from the syringe mechanism and placed into a separate dispenser assembly with its own plunger. This extraction allows the dispenser plunger to be actuated independently, providing precise control over the dispensed volume without being coupled to the syringe plunger's motion.
3Measurement precision
If the dispenser plunger extends through the measuring cavity to evacuate material, then accurate incremental dispensing is achieved, but the risk of fluid bypass increases
Solution Approach 1:
The tip portion of the dispenser plunger serves as an intermediary sealing element that moves through the measuring cavity. As it moves, it maintains contact with the cavity walls to prevent fluid bypass while allowing the plunger to evacuate the measured volume, thus achieving both accurate dispensing and maintaining seal integrity.
4Measurement precision
If the nozzle portion defines a fluid flow path with a measuring cavity, then precise volume measurement is enabled, but the device complexity increases
Solution Approach 1:
The measuring cavity is merged with the nozzle portion structure, combining the fluid flow path and volume measurement functions into a single integrated component. This merging enables precise volume measurement while minimizing additional device complexity by utilizing existing structural elements.
Data Source
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AI summary
A dispenser (100) for dispensing a predetermined amount of material from a prefilled syringe (102) is provided. The dispenser includes a dispenser body (104) and a plunger (124). The dispenser body (104) includes a syringe mounting region (108) and a nozzle portion (164) through which the material is dispensed. The nozzle portion (164) has a syringe dispensing end receiving cavity (168) configured to mate with the dispensing end (118) of the syringe (102) and an outlet (172). A fluid flow path fluidly communicates the syringe dispensing end receiving cavity (168) with the outlet (172) and includes a measuring cavity (180) having a predetermined volume. The plunger (124) is carried by the dispenser body (104). The plunger (124) has a retracted state in which the plunger (124) is retracted from the measuring cavity (180) such that the outlet (172) is in fluid communication with the syringe dispensing end receiving cavity (168). The plunger (124) has a depressed state in which the plunger (124) extends through the measuring cavity (180) to evacuate material from the measuring cavity (180).