Variable-Inductance Resonant Sensors for Vascular Signal Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing resonant circuit-based vascular monitors face challenges in accurately detecting and interpreting changes in inferior vena cava dimensions due to its unique physiology, which leads to paradoxical geometry and motion changes, and issues with signal detection and interference from electromagnetic noise.
Innovation Solution
Implementing a wireless resonant circuit sensor with a variable inductance coil that adjusts excitation frequency dynamically, uses signal processing algorithms like FFT and Zoom FFT for real-time frequency detection, and employs characterization curves to translate sensor signals into physiological parameters, while mitigating interference through background noise assessment and hardware validation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the excitation frequency is fixed, then the device complexity is reduced, but the measurement precision deteriorates due to frequency drift and environmental interference
Solution Approach 1:
The patent implements dynamic frequency adjustment by continuously sweeping through a range of excitation frequencies and identifying the frequency that produces the maximum ring-back signal amplitude. This dynamic approach allows the system to track resonant frequency drift caused by environmental changes, temperature variations, or physiological changes, thereby maintaining measurement precision without requiring an overly complex fixed-frequency control mechanism.
Solution Approach 2:
The system employs feedback by monitoring the amplitude of the ring-back signal and using this information to adjust the excitation frequency. The controller identifies the frequency corresponding to the maximum signal amplitude and adjusts subsequent excitation frequencies accordingly, creating a closed-loop system that maintains optimal measurement conditions despite external disturbances.
2Measurement precision
If the receiving amplifier gain is increased to detect weak signals, then the measurement precision improves, but harmful factors increase due to signal saturation and distortion
Solution Approach 1:
The receiving amplifier gain is adjusted dynamically based on the detected signal amplitude. When weak signals are detected, the gain is increased to improve measurement precision. When strong signals are detected that approach saturation levels, the gain is reduced to prevent distortion. This dynamic gain adjustment allows the system to optimize signal detection across varying signal conditions without introducing harmful saturation effects.
Solution Approach 2:
The system uses feedback from the detected signal amplitude to control the receiving amplifier gain. The controller monitors the signal level and adjusts the gain accordingly, creating a closed-loop automatic gain control system that prevents saturation while maximizing the detection of weak signals.
3Device complexity
If background noise is not assessed, then the device complexity is reduced, but the measurement precision deteriorates due to electromagnetic interference
Solution Approach 1:
The system performs preliminary background noise assessment before conducting the actual measurement. By characterizing the electromagnetic noise environment in advance, the system can establish baseline noise levels and filtering thresholds that improve the accuracy of subsequent measurements. This preliminary action allows the system to distinguish between background noise and actual physiological signals more effectively.
Solution Approach 2:
The noise assessment results are fed back into the signal processing algorithm to adjust filtering parameters and threshold settings. This feedback mechanism allows the system to adapt to varying noise conditions and maintain measurement precision even in electromagnetically noisy environments.
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
Enhances the accuracy and reliability of vascular monitoring by optimizing excitation frequency, reducing interference, and improving signal fidelity, thereby providing precise physiological readings.
Implementation Method 1
Resonant circuit (RC)-based sensors are sensors that deliver a change in resonant frequency as a result of a change in a physical parameter in the surrounding environment, which change causes the resonant frequency produced by the circuit within the device to change
Implementation Method 2
an electromagnetic transmitter sends energy to a resonant circuit sensor to produce a ring-back signal
Data Source
AI summary
Systems and methods for control and signal processing in variable inductance, resonant circuit vascular monitoring devices including use of sensor signal magnitude for determining and interpreting sensed parameters are disclosed.