Phase-decorrelation OCT for Viscosity Measurement

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Solution Overview

Problem

Current methods for measuring viscosity and microscale dynamics of biological fluids and tissues are limited by sensitivity to bulk motion and lack of precision, making accurate in vivo and in situ measurements challenging.

Innovation Solution

The use of phase-decorrelation optical coherence tomography (PhD-OCT) to measure microscale dynamics by generating and analyzing optical signals, allowing for the calculation of quantitative parameters such as viscosity and viscoelasticity through phase and amplitude information, with a system that includes a PhD-OCT scanner and scanning controller to implement scanning sequences and process data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional OCT methods are used to measure viscosity and microscale dynamics, then measurement capability is provided, but sensitivity to bulk motion causes reduced measurement precision

Engineering Contradiction:

Improveviscosity measurement precisionVSAvoidbulk motion sensitivity

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent extracts and isolates the phase information from the OCT signal to specifically measure microscale dynamics. By separating the phase component from the full OCT signal and analyzing only phase variations between consecutive scans, the method eliminates sensitivity to bulk motion while preserving sensitivity to microscopic particle movements, thereby resolving the contradiction between measurement precision and bulk motion sensitivity

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the measurement parameter from intensity-based OCT signals to phase-based OCT signals. By tracking phase shifts of light scattered by particles between consecutive scans, the system achieves high sensitivity to microscale dynamics while being inherently insensitive to bulk motion, as phase changes only occur when particles move relative to the scattering medium

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If phase information is used to measure microscale dynamics, then measurement sensitivity is improved, but sensitivity to bulk motion increases

Engineering Contradiction:

Improvemicroscale dynamics detection sensitivityVSAvoidbulk motion sensitivity

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent segments the phase measurement into two components: bulk motion (affecting all pixels uniformly) and microscale dynamics (affecting individual pixels). By computing phase differences between consecutive scans and analyzing the statistical distribution of these differences, the method isolates microscale dynamics from bulk motion, achieving high sensitivity to particle movements while rejecting bulk motion effects

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of trying to eliminate bulk motion directly, the patent inverts the approach by exploiting the fact that bulk motion affects all measurements uniformly while microscale dynamics create variations. By analyzing the variance and distribution of phase differences rather than absolute phase values, the system converts the harmful bulk motion sensitivity into a useful reference frame, where bulk motion becomes the baseline and deviations represent true microscale dynamics

Inventive Principle:

Principle #13The other way round (Inversion)

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, sensitive measurements of viscosity and viscoelasticity with reduced sensitivity to bulk motion, facilitating in vivo and in situ applications, and providing insights into disease diagnosis and tissue stiffness mapping.

Implementation Method 1

phase-decorrelation optical coherence tomography (Phd-OCT) scanner configured to implement a scanning sequence via an optical signal on a sample medium

Methodology Applied

Scientific EffectOptical coherence tomography:

Implementation Method 2

obtain phase and amplitude information associated with a reflected version of the optical signal

Methodology Applied

Scientific EffectPhase information detection:

Data Source

PatentUS11069055B2Phase-decorrelation optical coherence tomography-based parameter measurement

Publication Date: 2021.07.20 THE CLEVELAND CLINIC FOUND

AI summary

One example includes a scanning system. The system includes a phase-decorrelation optical coherence tomography (PhD-OCT) scanner configured to implement a scanning sequence via an optical signal on a sample medium. The system also includes a scanning controller configured to provide control signals to the PhD-OCT scanner to implement the scanning sequence and to obtain phase and amplitude information associated with a reflected version of the optical signal. The phase and amplitude information can be indicative of microscale dynamics of the sample medium. The scanning controller can also implement an algorithm to calculate a quantitative parameter of the sample medium based on the phase and amplitude information associated with the sample medium.