Creatinine Sensor Calibration With Stable Creatine Ratio Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current creatinine and creatine sensors face challenges in maintaining stable calibration solutions due to the reversible hydrolysis of creatinine to creatine, leading to errors in concentration measurements, which are exacerbated by temperature and age, limiting their accuracy and shelf-life.
Innovation Solution
A 3-point calibration process using calibration solutions with stable and unstable creatine/creatinine ratios, combined with external correction solutions, to accurately determine sensor sensitivities and correct for concentration changes, ensuring accurate creatinine and creatine measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If calibration solutions are stored at room temperature for extended periods, then the sensors can be used longer, but the creatinine to creatine ratio changes due to hydrolysis, causing calibration errors
Solution Approach 1:
The patent changes the storage temperature parameter from room temperature to refrigerated conditions (2-8°C) to slow down the hydrolysis reaction rate of creatinine to creatine. This temperature parameter change extends the shelf-life while maintaining calibration accuracy by preserving the stable creatinine to creatine ratio in the calibration solutions.
2Ease of manufacture
If the creatinine to creatine ratio in calibration solutions is not stable, then calibration can be performed, but measurement errors are introduced that propagate to all sample results
Solution Approach 1:
The patent performs preliminary stabilization of the creatinine to creatine ratio by storing calibration solutions at refrigerated temperatures before use. This preliminary action ensures that the ratio remains stable during the calibration process, preventing measurement errors from propagating to sample results while maintaining ease of calibration.
3Measurement precision
If calibration solutions are prepared fresh, then measurement accuracy is maintained, but the workflow becomes more complex and time-consuming
Solution Approach 1:
The patent prepares calibration solutions in advance and stores them at refrigerated temperatures to maintain stability. This preliminary preparation eliminates the need for fresh preparation at the time of measurement, simplifying the workflow while maintaining accuracy through proper storage conditions that preserve the creatinine to creatine ratio.
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 method provides stable calibration over extended periods, minimizing measurement errors and extending the shelf-life of the sensors, enabling precise detection of creatinine and creatine levels in biological samples.
Implementation Method 1
the final reaction product of hydrogen peroxide (H2O2) may then be electrochemically oxidized on the platinum electrode under a constant polarization potential and used to measure creatinine and/or creatine levels
Implementation Method 2
creatininase, creatinase, and sarcosine oxidase that catalyze the production of glycine, formaldehyde, and hydrogen peroxide from creatinine and water
Implementation Method 3
an enzymatic biosensor containing three enzymes—creatininase, creatinase, and sarcosine oxidase—that catalyze the production of glycine, formaldehyde, and hydrogen peroxide from creatinine and water
Data Source
AI summary
Techniques includes measuring, using a creatine sensor, a creatine sensor current signal (ΔI2) of a first calibration solution (CS2). A creatine sensor sensitivity (Slope) for the creatine sensor is based on the creatine sensor current signal (ΔI2). The first calibration solution (CS2) has a known concentration of creatine (CR_CS2), a known concentration of creatinine (CREA_CS2), and a stable ratio of creatine to creatinine over a range of temperatures for a predefined shelf-life of the first calibration solution (CS2). The Techniques include measuring, using the creatine sensor, a measured creatine concentration (MCR_CS3) of a second calibration solution (CS3). The second calibration solution (CS3) has an initial known creatine concentration (CR_CS3), an initial known creatinine concentration (CREA_CS3), and an unstable ratio of creatine to creatinine that changes over the predefined shelf-life. Concentrations of creatine and creatinine in a sample are thereafter estimated.