Active Measuring Circuit for ChemFET Biomarker Detection

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Solution Overview

Problem

Existing measurement circuits for chemically sensitive field effect transistors (ChemFET) and ion-sensitive field effect transistors (ISFET) face challenges in achieving low power consumption and compact size, making them unsuitable for portable devices due to the need for multiple power sources and higher energy consumption.

Innovation Solution

A measurement circuit utilizing an organic electrochemical transistor, ChemFET, or ISFET with a bridge circuit and operational amplifier, configured to operate with a minimal number of components, including transistors, resistance components, and a power source, allowing for low power consumption and compact design, enabling linear detection of substance concentrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple constant power sources (current sources and voltage sources) are used in measurement circuits, then measurement accuracy is improved, but power consumption increases and device size increases

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidpower consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent combines multiple power source functions into a single constant voltage source. The bridge circuit integrates both voltage reference and current regulation functions, eliminating the need for separate current and voltage sources while maintaining measurement accuracy through the operational amplifier's feedback control.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single constant voltage source serves multiple functions: it provides the reference voltage for the bridge circuit, powers the operational amplifier, and enables current regulation through the feedback mechanism. This multi-functional design reduces component count and power consumption while maintaining measurement precision.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Measurement precision

If multiple constant power sources (current sources and voltage sources) are used in measurement circuits, then measurement accuracy is improved, but device complexity increases

Engineering Contradiction:
Improvemeasurement accuracyVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges multiple power source components into a unified bridge circuit architecture. The operational amplifier and feedback network integrate voltage reference, current regulation, and signal amplification functions into a single coherent system, reducing component count and simplifying the overall device structure.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The operational amplifier acts as an intermediary that mediates between the single constant voltage source and the measuring transistor. It provides feedback control to regulate current flow and maintain measurement accuracy without requiring separate current sources, thereby simplifying the device architecture.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Area of stationary object

If a compact measurement circuit design is implemented, then device size is reduced, but power consumption management becomes more challenging

Engineering Contradiction:
Improvedevice sizeVSAvoidpower consumption management
Core Design Contradiction:
Area of stationary objectVSUse of energy by stationary object

Solution Approach 1:

The patent combines power management and measurement functions into a single integrated bridge circuit. The operational amplifier and feedback network enable precise power control within the compact design, allowing the circuit to maintain low power consumption while achieving accurate measurements in a small footprint.

Inventive Principle:
Principle #5Merging (Combining)

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 solution enables low-power, compact, and efficient measurement of biomarker concentrations, suitable for wearable devices, with reduced energy consumption and simplified evaluation of output signals, facilitating continuous monitoring of patient-specific biomarkers.

Implementation Method 1

a field-effect transistor (211), in particular an organic electrochemical transistor (OECT), a chemically sensitive field effect transistor (ChemFET) or an ion-sensitive field effect transistor (ISFET)

Methodology Applied
Scientific EffectField-effect transistor sensing:

Data Source

PatentEP4379366A1Active measuring circuit and method for operating an active measuring circuit
Publication Date: 2024.06.05 PG40 CONSULTING GRP GMBH
  • EP4379366A1 patent drawingFigure 1A
  • EP4379366A1 patent drawingFigure 1B
  • EP4379366A1 patent drawingFigure 2A

AI summary

According to various embodiments, the application includes an active measuring circuit (100): an electrical power source (110), a bridge circuit (200), wherein a bridge input node (201) of the bridge circuit (200) and a bridge output node (202) of the bridge circuit (200) are connected to the electrical power source (110), wherein a field-effect transistor (211) and a first resistor (212) form a first bridge branch (210) of the bridge circuit (200) between the bridge input node (201) and the bridge output node (202), wherein a second resistor (221) and a third resistor (222) form a second bridge branch (220) of the bridge circuit (200) between the bridge input node (201) and the bridge output node (202), and wherein an operational amplifier (230) forms a bridge branch between the first bridge branch (210) and the second bridge branch (220) of the bridge circuit (200) forms,and wherein the operational amplifier (230) is connected to a gate contact of the field-effect transistor (211).