Variable Flow Resistor for Constant Infusion Rate
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Solution Overview
Problem
Current infusion technologies, particularly infusion pumps, face issues with accuracy and patient safety, contributing to significant medical errors and recalls, as they often lack features to maintain a constant flow rate and may be prone to human factors and hardware issues.
Innovation Solution
An infusion device with a plunger situated within a vessel to define a chamber, featuring a variable flow resistor in the outflow path that adjusts resistance to maintain a constant fluid flow rate as the force on the plunger decreases, ensuring accurate and safe infusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a spring-powered plunger is used to drive fluid flow, then the device is simple and inexpensive, but the flow rate varies as the spring force decreases during infusion
Solution Approach 1:
The flow resistor is designed with a variable resistance characteristic that changes during the infusion process. As the spring force decreases, the resistor's resistance increases, maintaining a substantially constant flow rate. This dynamic adjustment resolves the contradiction between simple device design and accurate flow rate control.
2Manufacturing precision
If a variable flow resistor is added to maintain constant flow rate, then flow rate accuracy improves, but device complexity increases
Solution Approach 1:
The flow resistor is designed to automatically adjust its resistance based on the decreasing spring force without requiring external control mechanisms. The resistor's variable resistance characteristic inherently compensates for the changing drive force, maintaining constant flow rate through self-regulation rather than complex active control.
3Manufacturing precision
If electric pumps are used to achieve accurate flow rates, then flow rate accuracy improves, but cost and device complexity increase
Solution Approach 1:
The invention replaces complex electric pump mechanisms with a simpler mechanical system consisting of a spring-powered plunger and a variable flow resistor. The variable resistor passively maintains constant flow rate through its resistance characteristics, eliminating the need for motors, sensors, and control electronics while achieving comparable flow rate accuracy.
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 device ensures a substantially constant flow rate throughout the infusion process, reducing the risk of medical errors and improving patient safety by maintaining accurate fluid delivery despite variations in the force applied to the plunger.
Implementation Method 1
A variable flow resistor is situated within the outflow path and being configured to vary resistance to fluid flow from the chamber
Implementation Method 2
fluid in the chamber can be dispensed upon displacement of the plunger by a force acting thereon
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
Systems and methods for infusion of fluids using stored potential energy and a variable flow resistor. In one aspect of the present disclosure, there is provided an infusion device that includes a plunger situated within a vessel so as to define a chamber within which a volume of fluid can be accommodated between a downstream surface of the plunger and the vessel. The infusion device further includes an outflow path through which the fluid in the chamber can be dispensed upon displacement of the plunger by a force acting thereon. A variable flow resistor is situated within the outflow path and is configured to allow a substantially constant fluid flow rate from the vessel to be maintained as the force acting on the plunger decreases.