Infusion Drive Blocking Mechanism for Coupling Control
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Solution Overview
Problem
Ambulatory infusion devices face issues with precise dosing due to undefined coupling between the piston and plunger rod, leading to unintended drug delivery or under-pressure, which can result in serious medical complications.
Innovation Solution
Incorporating a blocking device with movable blocking members that control the mechanical coupling between the pump drive and dosing unit, allowing for well-defined coupling and decoupling, preventing piston displacement and ensuring proper operational configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a syringe-driver system is used with a piston and plunger rod, then liquid drug can be administered continuously, but the coupling between piston and plunger rod may be undefined leading to unintended drug delivery or under-pressure
Solution Approach 1:
The blocking device is activated before the coupling operation to prevent any unintended piston displacement. The blocking member is positioned to block the piston coupler's movement path in advance, ensuring that even if misalignment occurs during coupling, the piston cannot be displaced unintentionally. This preliminary blocking action resolves the contradiction by maintaining dosing precision while allowing continuous administration capability.
Solution Approach 2:
The blocking member acts as an intermediary safety mechanism between the plunger rod and the piston. It mediates the coupling process by temporarily preventing piston movement, allowing the mechanical coupling to be established or released without transmitting force to the piston. This intermediary blocking function ensures reliable dosing while maintaining the productivity of continuous administration.
2Ease of operation
If the plunger rod is in a more advanced position as compared to the piston, then coupling can be established, but the piston is pushed forward resulting in unintended drug delivery
Solution Approach 1:
The blocking device applies preliminary anti-action by blocking the piston coupler's movement path before any unintended piston displacement can occur. When the plunger rod is in an advanced position during coupling, the blocking member prevents the piston coupler from contacting and pushing the piston forward. This preliminary blocking counteracts the potential harmful effect of unintended drug delivery while allowing the coupling to be established.
3Ease of operation
If the plunger rod is in a more retracted position as compared to the piston, then coupling can be established, but the piston may be retracted resulting in under pressure or improper engagement
Solution Approach 1:
The blocking device applies preliminary anti-action by preventing the piston coupler from being pulled back when the plunger rod is in a retracted position. The blocking member blocks the movement path of the piston coupler, stopping any retraction force from being transmitted to the piston. This prevents under-pressure conditions and ensures proper engagement while maintaining ease of coupling operation.
4Reliability
If a blocking device is added to control coupling, then piston displacement is prevented ensuring dosing precision, but device complexity increases
Solution Approach 1:
The blocking function is extracted as a separate, dedicated component (blocking device with blocking member) rather than being integrated into the existing plunger rod or piston structure. This extraction allows the blocking mechanism to be designed independently with minimal complexity, focusing solely on the critical safety function of preventing unintended piston displacement while maintaining dosing precision.
Solution Approach 2:
The blocking device is designed to be automatically controlled based on the pump drive configuration. The system self-regulates the blocking state without requiring additional complex control mechanisms - when the pump drive is in a pre-determined configuration, the blocking member is automatically positioned to block or enable coupling as needed. This self-service approach minimizes device complexity while ensuring dosing precision.
Data Source
AI summary
Disclosed is an infusion device drive unit that includes a pump drive configured to operatively mechanically couple to a dosing unit to control operation of the dosing unit. The infusion device drive unit further includes a blocking member that is movable between a blocking configuration and a enabling configuration, the blocking member enabling the establishing and/or the releasing of an operative mechanical coupling between the pump drive and the dosing unit in the enabling configuration and preventing the establishing and/or the releasing of an operative mechanical coupling between the pump drive and the dosing unit in the blocking configuration. The infusion device drive unit controls the blocking member to take on the enabling configuration if the pump drive is in at least one pre-determined configuration and to take on the blocking configuration if the pump drive is in a configuration different from a pre-determined configuration.