Medical Administration Barrel Grooves for Piston Sealing
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Solution Overview
Problem
The vacuum piston placement process often results in a large headspace between the piston and the substance in medical administration barrels, which can lead to piston retraction due to environmental changes and is problematic during substance dispensing.
Innovation Solution
A medical administration barrel with grooves in its interior wall allows fluid to bypass the piston, enabling the piston to be advanced further into the barrel, minimizing headspace through a vacuum enclosure and pressure differential.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If vacuum piston placement process is used, then piston sealing is achieved, but large headspace remains between piston and substance
Solution Approach 1:
The barrel interior wall is segmented with grooves that divide the space and allow fluid to bypass the piston during advancement, enabling the piston to travel further into the barrel and reduce headspace volume while maintaining sealing integrity
Solution Approach 2:
The piston is advanced further into the barrel by changing the fluid dynamics parameters - allowing fluid to flow through grooves during piston movement, which enables greater piston displacement and reduced headspace while maintaining the vacuum seal
2Volume of moving object
If smaller container is used to minimize headspace, then headspace volume is reduced, but space for administration system is insufficient
Solution Approach 1:
The grooves are positioned at specific locations on the barrel interior wall, utilizing the radial dimension to allow fluid bypass paths that do not interfere with the axial space required for the administration system, thus reducing headspace while maintaining system accommodation
3Volume of moving object
If piston is advanced further to minimize headspace, then headspace volume is reduced, but piston may retract due to environmental changes
Solution Approach 1:
The grooves are pre-positioned on the barrel interior wall to allow controlled fluid bypass during piston advancement, enabling the piston to reach an optimized position that minimizes headspace while the sealing mechanism is already in place to prevent subsequent retraction from environmental changes
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 solution effectively reduces the headspace between the piston and the substance, enhancing the sealing process and preventing piston retraction, while allowing space for administration systems and maintaining an airtight seal.
Implementation Method 1
The exterior of the piston and container assembly is thereafter restored to atmospheric pressure, such that a pressure differential is created across the piston between the proximal and distal surfaces thereof. The pressure differential drives the piston down the barrel
Implementation Method 2
The at least one groove permits fluid to bypass the piston when positioned along the at least one groove
Implementation Method 3
Generally, the piston and the pre-filled container are exposed to a vacuum, i.e., a pressure lower than atmospheric pressure
Data Source
AI summary
A barrel is provided having open proximal end and a closed distal end, and at least one groove in an interior wall thereof. The groove(s) define a length extending a distance from the open end of the barrel toward the distal end of the barrel and defining a substantially constant depth and width along the length thereof. A piston is in sealing engagement with the interior wall of the barrel. The groove(s) permits fluid to bypass the piston when positioned along the groove(s). At least a portion of the piston is positioned distally from the groove(s), thereby sealing substance within the barrel.