Oxygen Sensor Calibration via Ambient Air Reference
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for monitoring kidney function, particularly in patients post-surgery, face challenges in accurately measuring oxygenation status due to the inaccessibility of kidneys, leading to potential delays in detecting acute kidney injury (AKI) and subsequent complications.
Innovation Solution
The development of medical devices and systems that include calibrated oxygen sensors, which can be used with Foley catheters to measure oxygen partial pressure in urine, allowing for real-time monitoring of kidney function and early detection of AKI risks by processing circuitry that calibrates the sensors based on ambient air and atmospheric pressure signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional kidney function monitoring methods are used, then monitoring can be performed with existing equipment, but measurement accuracy is insufficient due to kidney inaccessibility
Solution Approach 1:
The patent uses urine as an intermediary substance to indirectly measure kidney oxygenation status. Since kidneys are inaccessible for direct measurement, the system measures oxygen partial pressure in urine (which is produced by the kidneys) as a proxy indicator of kidney function and oxygenation status, thereby resolving the measurement difficulty caused by organ inaccessibility
Solution Approach 2:
The patent replaces traditional mechanical/invasive kidney monitoring methods with an optical sensing system. An oxygen sensor (likely optical-based) measures oxygen partial pressure in urine non-invasively, substituting complex mechanical access to the kidneys with a simpler fluid analysis approach that achieves higher measurement precision
2Reliability
If oxygen sensors are used without calibration, then device complexity is reduced, but measurement reliability deteriorates
Solution Approach 1:
The patent implements preliminary calibration of the oxygen sensor using ambient air as a reference standard before actual urine measurements. The system exposes the sensor to known oxygen concentrations in ambient air to establish baseline calibration parameters, ensuring measurement reliability is established in advance before clinical use
Solution Approach 2:
The calibration system uses readily available ambient air as its own calibration reference, eliminating the need for external calibration gases or complex calibration equipment. The sensor calibrates itself by comparing readings against the known oxygen composition of ambient air, reducing device complexity while maintaining reliability
3Measurement precision
If ambient air calibration is implemented, then calibration accuracy is improved, but additional sensors and processing requirements increase device complexity
Solution Approach 1:
The oxygen sensor serves multiple functions: it measures oxygen partial pressure in both ambient air (for calibration) and in urine (for clinical measurement). This multi-functionality allows the same sensor to perform both calibration and measurement tasks, reducing the need for separate calibration sensors and simplifying the overall device architecture
Solution Approach 2:
The system changes the operational parameter of the oxygen sensor between calibration mode (exposed to ambient air with known oxygen concentration) and measurement mode (exposed to urine with unknown oxygen concentration). By dynamically adjusting the reference standard based on operational mode, the system achieves high calibration accuracy without requiring permanently fixed calibration hardware
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 enables more accurate and timely monitoring of kidney function, reducing the risk of AKI by providing clinicians with precise oxygenation status data, facilitating early intervention and potentially minimizing hospital stays and complications.
Implementation Method 1
an oxygen sensor... to sense a partial pressure of oxygen in a fluid, such as urine
Implementation Method 2
an atmospheric pressure sensor, an atmospheric pressure sensor signal indicative of atmospheric pressure
Data Source
AI summary
An example device includes processing circuitry configured to receive, from an oxygen sensor, an ambient air signal indicative of an oxygen partial pressure of ambient air. The processing circuitry is further configured to receive, from an atmospheric pressure sensor, an atmospheric pressure sensor signal indicative of atmospheric pressure. The processing circuitry is configured to determine, based on the atmospheric pressure sensor signal, an oxygen partial pressure of the ambient air, determine, based at least in part on the oxygen partial pressure of the ambient air and the ambient air signal, the one or more calibration parameters, and calibrate, based on the one or more calibration parameters, the oxygen sensor. The calibrated oxygen sensor may be used to, for example, determine the oxygen content of urine of a patient to monitor renal function of the patient.