Fluid Injector Impedance Modeling for Flow Spike Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Medical fluid injection systems face challenges with fluid flow rate spikes and inaccurate mixing ratios due to impedance and capacitance issues, leading to under-delivery or over-delivery of fluids during multiphase injections, particularly when transitioning between contrast agents and saline solutions.
Innovation Solution
The system models and adjusts factors affecting impedance, such as temperature, viscosity, and pressure, to control fluid delivery, using sensors to monitor and adjust flow rates and pressures dynamically, ensuring a stable and accurate delivery of fluids by recalculating piston positions and flow rates in real-time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If pressure is applied to the contrast agent at the start of injection, then fluid flow is initiated, but backflow occurs into the saline fluid path reducing flow rate accuracy
Solution Approach 1:
The system performs preliminary priming of the fluid path with saline before contrast agent injection. This preliminary action ensures the fluid path is properly conditioned and prevents backflow of contrast agent into the saline path during the injection process, thereby maintaining flow rate accuracy.
Solution Approach 2:
The system uses sensors to monitor pressure and flow rate in real-time during injection. Based on this feedback, the controller dynamically adjusts piston positions and injection parameters to compensate for backflow effects and maintain accurate flow rate delivery.
2Speed
If the catheter exit area is reduced to increase fluid velocity, then kinetic energy is generated, but energy is lost from the system
Solution Approach 1:
The system converts the kinetic energy that would otherwise be lost at the catheter exit into useful work by using it to drive the fluid delivery process. The pressure differential created by the piston is optimized to maintain steady flow while minimizing energy loss, effectively utilizing the kinetic energy component in the overall fluid delivery system.
3Reliability
If saline is injected immediately after contrast agent, then fluid path is flushed, but flow rate spikes occur due to viscosity differences
Solution Approach 1:
The system dynamically adjusts the injection parameters for saline based on the previous contrast agent injection. The controller modifies piston positions, injection speeds, and pressure differentials in real-time to compensate for the viscosity difference between contrast agent and saline, preventing flow rate spikes while ensuring proper flushing.
Solution Approach 2:
The system changes key parameters such as injection pressure, flow rate, and piston velocity when transitioning from contrast agent to saline. These parameter adjustments are calculated based on the viscosity characteristics of each fluid to maintain consistent and stable flow rates throughout the multiphase injection process.
4Measurement precision
If multiple fluids are delivered simultaneously, then mixing ratio can be controlled, but impedance variations cause delivery inaccuracies
Solution Approach 1:
The system employs sensors to continuously monitor pressure, flow rate, and fluid characteristics during simultaneous multi-fluid delivery. This feedback is used by the controller to dynamically adjust piston positions and injection parameters, compensating for impedance variations and maintaining accurate mixing ratios and delivery precision.
Solution Approach 2:
The controller dynamically modifies injection parameters such as pressure differential, flow rate, and piston velocity for each fluid based on real-time impedance measurements. These parameter changes ensure that despite variations in fluid viscosity and impedance, the system maintains accurate mixing ratios and delivery accuracy throughout the injection process.
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 approach reduces the likelihood of fluid flow rate spikes and achieves more precise and consistent fluid mixing ratios, improving the accuracy and efficiency of fluid delivery during medical procedures.
Implementation Method 1
The system models and adjusts factors affecting impedance, such as temperature, viscosity, and pressure, to control fluid delivery
Implementation Method 2
measuring one or more characteristic of the fluid delivery; modeling one or more factor that affects impedance... based upon one or more measurement of the one or more characteristic
Implementation Method 3
initiating delivery of at least a first fluid to a patient at a first flow rate... adjusting one or more characteristic of the fluid injection system... to improve fluid delivery performance
Data Source
AI summary
A fluid injector system for delivering a multi-phase fluid injection to a patient and methods of fluid delivery is disclosed. Methods of creating and using a multi-aspect fluid path impedance model of the injector system are used. Modeling and adjustment of factors that affect impedance and prevent or reduce backflow, reduce the likelihood of fluid flow rate spikes and provide more accurate flow rates and mixing ratios of fluids may be repeated or happen essentially continuously during an injection. The adjustments may be determined before the injection or determined and/or adjusted during the injection. The determination may include sensor feedback commonly used in injectors such as pressure and position feedback as well as other sensors. In all cases, the user can be notified of adjustments through on-screen notices and/or through the recordation of the injection data by a control device of the injector at the conclusion of the injection.