Blood Cholesterol Sensor with Separating Pad for Interference Removal
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Solution Overview
Problem
Current methods for detecting total cholesterol in blood samples, especially using whole blood, are inconvenient, unstable for low concentrations, and prone to interference from corpuscles, requiring preprocessing and complex setups, which limits their use for rapid and accurate detection outside laboratory settings.
Innovation Solution
A sensing member with a working and counter electrode, a reactive pad containing electron transport material and enzyme, and a separating pad to remove interfering materials, allowing whole blood samples to be quickly and accurately analyzed for total cholesterol levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If spectrophotometric method is used for cholesterol detection, then detection can be performed with standard instrumentation, but the method requires preprocessing steps (centrifuging, depositing, separating) and is limited to laboratory settings
Solution Approach 1:
The device is segmented into distinct functional zones: a separation zone with a separating film that removes corpuscles, and a detection zone with the working electrode. This segmentation allows the complex preprocessing function to be isolated in a dedicated zone, eliminating the need for external centrifuging and separation equipment while maintaining detection accuracy.
Solution Approach 2:
A separating film is introduced as an intermediary component between the sample application and the detection electrode. This film acts as a mediator that automatically separates corpuscles from plasma through capillary action and filtration, eliminating the need for manual preprocessing steps while ensuring accurate cholesterol detection.
2Ease of operation
If whole blood sample is used directly for detection, then convenience is improved, but interfering materials (corpuscles) affect detection results
Solution Approach 1:
The separating film is pre-positioned in the detection device to perform preliminary separation of corpuscles from plasma before the sample reaches the detection electrode. This preliminary action ensures that only plasma containing cholesterol reaches the electrode, maintaining detection accuracy while allowing direct application of whole blood samples.
Solution Approach 2:
The interfering corpuscles are extracted from the whole blood sample by the separating film, which allows plasma to pass through to the detection zone while retaining corpuscles. This extraction process eliminates interference from blood cells and other particulate matter, enabling accurate detection from undiluted whole blood samples.
3Measurement precision
If horizontal chromatography is used for corpuscle separation, then plasma can reach the electrode reaction area, but the separating time is long and flow rate is difficult to control
Solution Approach 1:
The passive horizontal chromatography method is replaced with an active capillary-driven filtration system. The separating film utilizes capillary action to rapidly draw plasma through the film while retaining corpuscles, achieving separation in seconds rather than minutes and providing consistent, controllable flow rates without complex mechanical pumping systems.
Solution Approach 2:
A porous separating film is used to achieve rapid and controlled separation. The film's pore structure allows plasma to pass through quickly via capillary action while physically blocking corpuscles, achieving effective separation in a matter of seconds rather than the prolonged time required by horizontal chromatography methods.
4Measurement precision
If additional pumping mechanism is used for corpuscle filtering and plasma flowing, then detection can be achieved, but sample volume increases to several tens of microliter and reactive time reaches several tens of minutes
Solution Approach 1:
The detection device uses self-service capillary action to drive plasma through the separating film and to the detection electrode without requiring external pumping mechanisms. This self-driven system minimizes sample volume requirements to just a few microliters and achieves detection in minutes rather than tens of minutes, as the capillary forces automatically regulate flow rate and separation efficiency.
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
Enables rapid and accurate detection of total cholesterol in whole blood samples by effectively separating interfering materials, providing linearly proportional current intensity to cholesterol concentration, thus improving detection precision and convenience.
Implementation Method 1
a separating pad disposed between the first and second substrates, wherein the blood sample is passed through the separating pad such that interfering materials can be separated and removed from the blood sample
Implementation Method 2
the blood sample is laterally diffused to the reactive pad
Implementation Method 3
an electrochemical detecting method is a rapid and reliable approach, which uses a conducting electrode to detect electrical current positively proportional to the concentration of analyte of the sample transported by electrons generated in a biochemical reaction through an enzyme
Data Source
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AI summary
A sensing member for detecting total cholesterol of a blood sample is disclosed, which includes: a working electrode and a counter electrode respectively formed on a first substrate and a second substrate, wherein, an opening is formed in one of the first and second substrates corresponding in position to the electrode for allowing the blood sample to pass through; a dielectric layer formed on one of the surfaces of the first and second substrates and exposing the electrode and end connector such that the end connector can be electrically connected to an electronic device used for applying electric voltage; a reactive pad disposed between the working electrode and the counter electrode and containing an reactive reagent, wherein the reactive reagent comprises an electron transport material, an enzyme capable of reacting with the analyte and generating a current corresponding to the concentration, and a buffer solution; and a separating pad disposed on the opening for removing interfering materials from the blood sample before the blood sample enters into the opening. By disposing the separating pad at a specified position, corpuscles and interfering giant molecules can be removed from the blood sample so as to quickly and accurately detect total cholesterol of the whole blood sample.