Physiological Sensor Probe-Off Detection via Signal Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current medical devices, such as pulse oximeters, face challenges in determining when a physiological sensor is not properly positioned on a patient, leading to inaccurate readings due to ambient light interference and sensor detachment or misalignment.
Innovation Solution
The system analyzes detected light signals and ambient signals to identify behaviors like mimicking-equal, mimicking-parallel, and nonlinear scaling, using these analyses to determine if the sensor is properly positioned by comparing signal amplitudes and trends, and providing indicators for probe-off conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the sensor is positioned to measure physiological parameters, then measurement capability is improved, but the sensor becomes vulnerable to probe-off conditions and ambient light interference
Solution Approach 1:
The system continuously monitors the detected light signal characteristics and provides feedback to determine probe-off conditions. By analyzing whether the detected signal behaves similarly to ambient light signals (mimicking-equal or mimicking-parallel behavior), the system can detect when the sensor has become detached or mispositioned, and trigger appropriate responses to maintain measurement reliability.
Solution Approach 2:
The system performs preliminary analysis of light signal characteristics to establish baseline behavior before actual physiological measurements are taken. By pre-characterizing the relationship between emitted light and detected signals, the system can later distinguish between legitimate physiological variations and probe-off conditions, ensuring measurement precision is maintained.
2Measurement precision
If ambient light filtering is implemented to improve signal accuracy, then measurement precision is improved, but device complexity increases
Solution Approach 1:
Instead of using complex mechanical or optical filtering systems to block ambient light, the patent substitutes a software-based signal analysis approach. The system replaces physical filtering mechanisms with algorithmic differentiation between emitted light signals and ambient light signals by analyzing their behavioral characteristics, thereby maintaining measurement precision while avoiding additional hardware complexity.
Solution Approach 2:
The system changes the parameter being monitored from raw light intensity to signal behavior characteristics (whether the signal mimics ambient light patterns). By transforming the measurement parameter from amplitude alone to temporal and behavioral patterns, the system achieves ambient light rejection through parameter transformation rather than physical filtering.
3Reliability
If continuous monitoring of light signals is performed to detect probe-off conditions, then reliability is improved, but energy consumption increases
Solution Approach 1:
The system performs probe-off detection continuously by analyzing the temporal behavior of light signals over time. Rather than implementing high-frequency sampling, the system uses periodic analysis of signal characteristics to detect changes in probe positioning, balancing reliable detection with acceptable power consumption by leveraging the temporal patterns inherent in physiological and ambient light signals.
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 effectively differentiates between proper sensor positioning and probe-off conditions, reducing errors caused by ambient light and sensor misalignment, thereby enhancing the accuracy of physiological parameter measurements.
Implementation Method 1
A light source may be configured to emit photons received by a detector
Implementation Method 2
A detector may be configured to detect the light
Data Source
AI summary
A physiological monitoring system may determine a probe-off condition. A physiological sensor may be used to emit one or more wavelengths of light. A received light signal may be processed to obtain a light signal corresponding to the emitted light and an ambient signal. The signals may be analyzed to identify similar behavior. The system may determine whether the physiological sensor is properly positioned based on the analysis.