Paper-Based Sensor with Integrated Reference Colors for Quantitative Analysis

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Solution Overview

Problem

Paper-based sensors face limitations in accuracy due to colorimetric measurements, requiring manual comparison with reference cards and being unreliable for quantitative applications, and existing automated solutions are prone to variability with different cameras and lighting conditions.

Innovation Solution

A paper-based sensor system that integrates hydrophobic channels and printed reference colors on the substrate, enabling real-time quantitative analysis using a smartphone camera, with a software platform for colorimetric image processing to determine analyte concentrations, and a workflow for patient monitoring and feedback.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If manual color comparison with reference cards is used, then device complexity is reduced, but measurement precision deteriorates

Engineering Contradiction:

Improvedevice complexityVSAvoidmeasurement precision

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent merges the reference color card into the sensor substrate itself, creating an integrated structure where reference colors and test zones are printed on the same substrate. This eliminates the need for separate reference cards while providing machine-readable colorimetric data for precise quantitative measurement.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent replaces manual visual color comparison with automated digital image capture and processing. A camera captures the sensor, and software algorithms analyze the colorimetric data, substituting human visual assessment with machine-based quantitative measurement for improved precision.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If automated phone app reading is used, then ease of operation is improved, but reliability deteriorates due to variability with different cameras and lighting

Engineering Contradiction:

Improveease of operationVSAvoidreliability

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent incorporates standardized reference colors with known optical properties directly on the sensor substrate. These reference regions serve as internal calibration standards that compensate for variations in camera sensors and lighting conditions, allowing reliable quantitative measurement across different devices and environments.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses colorimetric parameters (reflectance, absorbance) measured at specific wavelengths as the basis for quantitative analysis. By measuring colorimetric properties rather than relying on human visual perception, the system achieves device-independent and lighting-independent measurement with high reliability.

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If paper-based sensors are used, then cost is reduced and multiplexing is improved, but measurement precision deteriorates due to colorimetric limitations

Engineering Contradiction:

ImprovecostVSAvoidmeasurement precision

Core Design Contradiction:

Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent employs colorimetric detection with multiple reference colors and test zones that undergo specific color changes in response to analyte presence. By using multiple wavelengths and colorimetric parameters, the system achieves quantitative measurement capability on low-cost paper substrates, overcoming the traditional limitation of paper-based sensors.

Inventive Principle:

Principle #32Color changes

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

Provides robust, accurate, and user-friendly real-time health monitoring with increased multiplexing capabilities and reduced variability, eliminating the need for separate reference cards and improving the reliability of results across different devices and lighting conditions.

Implementation Method 1

the paper-based sensor reacting to the test sample to generate one or more color indicators

Methodology Applied

Scientific EffectColorimetric reaction:

Implementation Method 2

performing colorimetric image processing of the captured image of the paper-based sensor to determine one or more colorimetric properties

Methodology Applied

Scientific EffectColorimetric measurement:

Data Source

PatentUS10175162B2Paper sensing and analytic service workflow methods and systems

Publication Date: 2019.01.08 XEROX CORP

AI summary

This disclosure provides a workflow method and system associated with a paper-based sensor. Specifically, provided is a paper-based sensor workflow including printing of customized security sensing information and bio-reagents to produce a paper-based sensor, applying a test material, such as, but not limited to, blood, to the paper-based sensor, capturing an image of the paper-based sensor and performing a colorimetric process; and performing one or more analytics to produce results associated with the test material.