Multi-Fluid Injector Flow Profile Control
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Solution Overview
Problem
Existing fluid delivery systems for medical diagnostic and therapeutic procedures often experience spikes in fluid flow rates, leading to inaccurate mixing ratios and increased risk of extravasation and catheter kickback.
Innovation Solution
A multi-fluid injection system that adjusts the flow profiles of contrast medium and saline to equalize pressures and flow rates, using check valves and a controller to manage pressure and flow, thereby reducing spikes in fluid flow rates and ensuring accurate mixing ratios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If pressure is applied to contrast medium resulting in pressure build up and initial backflow, then contrast medium can be injected into patient, but flow rate of contrast medium is reduced due to backflow and expansion in contrast medium bag or syringe
Solution Approach 1:
The system pre-pressurizes the saline line before contrast medium injection to equalize pressures between lines. This preliminary action prevents backflow of contrast medium into the saline syringe/bag during the high-pressure contrast injection phase, ensuring accurate flow rates and mixing ratios are maintained throughout the injection process.
2Speed
If pressure applied to saline is increased until resistance drops and saline is directed into contrast medium flow, then saline can be injected, but flow rate of saline increases rapidly due to stored pressure energy creating flow spikes
Solution Approach 1:
The system pre-pressurizes both the contrast medium and saline lines simultaneously before injection begins. This equalizes the pressure baseline in both lines, preventing the saline line from storing excess pressure energy that would cause rapid flow acceleration and spikes when injection starts.
Solution Approach 2:
The system uses flow sensors to monitor real-time flow rates of contrast medium and saline. The controller adjusts the drive mechanisms based on feedback signals to maintain stable, programmed flow rates and prevent turbulent flow conditions that cause flow spikes.
3Duration of action of moving object
If transition from contrast medium injection to saline injection occurs, then fluid delivery can be completed, but rapid increase in flow rate creates transition to turbulence causing oscillations in flow
Solution Approach 1:
The system dynamically adjusts the drive mechanisms for both contrast medium and saline injection based on real-time flow rate monitoring. During transition phases, the controller modulates drive speeds to maintain laminar flow conditions and prevent turbulent oscillations, ensuring stable flow throughout the entire injection duration.
Solution Approach 2:
Real-time feedback from flow sensors allows the controller to detect and correct flow instabilities during transitions between contrast medium and saline injection. The system adjusts drive parameters dynamically to maintain stable, laminar flow conditions throughout the procedure.
4Quantity of substance
If separate sources are used for contrast medium and saline, then fluids can be stored and delivered, but backflow of fluids causes saline or contrast medium contamination during injection
Solution Approach 1:
The system pre-pressurizes both fluid lines to equalize pressures before injection begins. This prevents backflow between the contrast medium and saline lines during high-pressure injection phases, maintaining fluid purity and preventing contamination while still using separate storage sources.
Solution Approach 2:
The system introduces pressure equalization as an intermediary mechanism between the separate contrast medium and saline sources. By using pressure equalization chambers or pre-pressurization mechanisms, the system prevents direct backflow between fluid lines while maintaining separate storage sources.
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 system effectively reduces spikes in fluid flow rates, ensuring accurate and precise delivery of contrast medium and saline, thereby minimizing the risk of extravasation and catheter kickback, and improving patient comfort and diagnostic efficacy.
Implementation Method 1
A first check valve is provided in the first fluid line between the first fluid source and the patient. A second check valve is provided in the second fluid line between the second fluid source and the patient.
Implementation Method 2
A controller is provided to adjust a flow profile of at least one of a first flow profile of a first flow rate and a second flow profile of a second flow rate to dampen a transient increase in an overall flow rate during a transition between delivering one of the first fluid and the second fluid to delivering the other of the first fluid and the second fluid.
Data Source
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AI summary
A method of maintaining an overall flow rate during a sequential delivery of at least two fluids to a patient's blood vessel includes delivering at least a first fluid into the patient's blood vessel at a first flow rate, delivering at least a second fluid into the patient's blood vessel at a second flow rate, and adjusting at least one of a first flow profile of the first flow rate and a second flow profile of the second flow rate to dampen a transient increase in the overall flow rate during a transition between delivering one of the first fluid and the second fluid to delivering the other of the first fluid and the second fluid.