Infusion Control Device with Dual Flow Paths for Bolus Reservoir Priming
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Solution Overview
Problem
Existing patient-controlled analgesia (PCA) devices lack efficient mechanisms for rapid priming and filling of bolus reservoirs while maintaining continuous basal infusion and preventing accidental or intentional overdoses.
Innovation Solution
A device with dual flow paths and an actuator that allows for priming, filling, and bolus delivery modes, featuring a basal restrictor tube for continuous infusion and a bolus reservoir that can be filled during basal infusion, with a lock-out mechanism to prevent immediate reactivation after bolus administration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single flow path is used for both basal infusion and bolus delivery, then device complexity is reduced, but the ability to maintain continuous basal infusion while rapidly filling bolus reservoir is compromised
Solution Approach 1:
The device divides the fluid delivery system into separate flow paths: a first flow path for continuous basal infusion and a second flow path with a bolus reservoir for rapid bolus delivery. This segmentation allows independent operation of basal and bolus functions, enabling the bolus reservoir to be filled rapidly through the second flow path without interrupting the continuous basal infusion through the first flow path.
Solution Approach 2:
The bolus reservoir is pre-filled with medication through the second flow path before bolus delivery is needed. The branch restrictor tube controls the filling rate during this preliminary action, and the lock-out mechanism prevents accidental reactivation during filling. This preliminary filling action enables rapid bolus delivery when needed without requiring interruption of basal infusion.
2Productivity
If bolus reservoir is filled rapidly, then bolus delivery readiness is improved, but risk of accidental overdose increases
Solution Approach 1:
The device performs preliminary filling of the bolus reservoir through the second flow path at a controlled rate determined by the branch restrictor tube. During this preliminary filling phase, the lock-out mechanism is activated to prevent accidental actuation. The system transitions to a locked state where the bolus valve remains closed even if the actuator is pressed, ensuring safety during the vulnerable filling period.
Solution Approach 2:
The lock-out mechanism acts as an intermediary safety barrier between the user's actuation input and the bolus valve. When activated during reservoir filling, it intercepts actuation signals and prevents them from opening the bolus valve, thereby mediating the conflict between user intent and safety requirements during the rapid filling phase.
3Reliability
If lock-out mechanism is activated during bolus reservoir filling, then safety against accidental overdose is improved, but device operation complexity increases
Solution Approach 1:
The lock-out mechanism is merged with the existing actuator and valve system. The same actuator that opens the bolus valve for bolus delivery also activates the lock-out mechanism during reservoir filling. The branch valve and bolus valve work together in a coordinated manner, with the lock-out function integrated into the valve control logic rather than being a separate independent system.
Solution Approach 2:
The actuator serves multiple functions: it opens the bolus valve for bolus delivery, activates the lock-out mechanism during reservoir filling, and controls the branch valve for priming. This multi-functionality reduces the need for separate control mechanisms and simplifies the overall device operation despite the added safety functionality.
4Productivity
If dual flow paths with separate valves are used, then ability to maintain basal infusion during bolus filling is improved, but device complexity increases
Solution Approach 1:
The device segments the fluid delivery into two independent flow paths: the first flow path with a basal restrictor tube for continuous basal infusion, and the second flow path with a bolus reservoir, bolus valve, and branch valve for bolus delivery. This segmentation allows simultaneous operation of basal and bolus functions through separate controlled pathways.
Solution Approach 2:
The device merges the control functions into a single actuator that coordinates both the bolus valve and branch valve. The actuator integrates multiple control capabilities: opening the bolus valve for bolus delivery, opening the branch valve for priming and filling, and activating the lock-out mechanism. This merging reduces the number of independent control components needed.
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
Enables rapid and efficient priming and filling of the bolus reservoir, maintaining constant basal flow rates and preventing overdoses by allowing self-administration of bolus doses without disrupting continuous medication delivery.
Implementation Method 1
The first branch including a branch restrictor tube dimensioned to allow fluid flow at a bolus filling rate
Implementation Method 2
The basal restrictor tube may be dimensioned to allow fluid flow through the first flow path at the basal rate of flow
Data Source
Figure 1
Figure 2A
Figure 2B~3
AI summary
A medical fluid control device includes an actuator that is selectively operable to cause fluid to be delivered from a fluid source to a patient at a basal rate of flow via a first flow path, or cause a bolus dose of fluid to be delivered from a bolus reservoir to the patient via a second flow path.