Hyperspectral Remote PPG for Tissue-Type Perfusion Analysis

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Solution Overview

Problem

Existing non-contact PPG imaging technologies fail to accurately differentiate between different tissue types within a single image, averaging perfusion differences that can indicate physiological or pathological conditions, such as ischemia or inflammation, leading to inadequate assessment of tissue health during procedures like intestinal anastomosis.

Innovation Solution

A system utilizing hyperspectral imaging and remote PPG sensing to classify tissue types, estimate oxygenation levels, and derive PPG perfusion maps, combining these to provide a comprehensive tissue status assessment by segmenting images into distinct tissue types and analyzing PPG amplitude and delay maps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If general PPG image analysis is used to monitor tissue perfusion, then large tissue areas can be covered, but different tissue types are averaged together losing physiological or pathological information

Engineering Contradiction:
Improvetissue area coverageVSAvoidtissue type differentiation
Core Design Contradiction:
Area of stationary objectVSMeasurement precision

Solution Approach 1:

The patent applies segmentation by dividing the imaged tissue area into distinct tissue type regions based on spectral characteristics. The system segments the image into different tissue types (e.g., intestine, fat, muscle) and performs separate PPG analysis for each segment, preventing averaging of different tissue types while maintaining comprehensive area coverage

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements local quality by applying tissue-specific analysis parameters and reference standards to each segmented tissue type. Each tissue region is analyzed with its own characteristics in mind, allowing precise measurement of perfusion changes specific to each tissue type rather than using a uniform analysis approach across all tissues

Inventive Principle:
Principle #3Local quality

2Ease of operation

If non-contact PPG imaging is used to monitor skin perfusion, then remote detection is achieved, but accurate differentiation between tissue types is not possible

Engineering Contradiction:
Improveremote detection capabilityVSAvoidtissue type classification
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent utilizes parameter changes by analyzing spectral parameters across multiple wavelengths to differentiate tissue types. The system measures reflectance or absorption at various wavelengths and uses these spectral parameter variations to classify tissue types, enabling accurate differentiation while maintaining non-contact operation

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces spectral analysis as an intermediary step between non-contact imaging and tissue characterization. The spectral information acts as a mediator that enables tissue type identification from remote images, bridging the gap between ease of operation and measurement precision

Inventive Principle:
Principle #24Intermediary (Mediator)

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 precise separation of perfusion and oxygenation measurements for different tissue types, enhancing the accuracy of tissue health assessment and reducing the risk of complications like leakage during surgical procedures by providing a more complete evaluation of tissue status.

Implementation Method 1

PPG imaging utilizes an off-the-shelf camera and a light source to remotely detect the dynamic changes in blood volume beneath the skin

Methodology Applied
Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 2

estimate a presence or level of tissue oxygenation for each tissue type

Methodology Applied
Scientific EffectSpectroscopy: Absorption Spectroscopy

Data Source

PatentEP4478939B1A system and method for tissue analysis using remote ppg
Publication Date: 2025.08.27 KONINKLIJKE PHILIPS NV
  • EP4478939B1 patent drawingFigure 1(a)~1(b)
  • EP4478939B1 patent drawingFigure 2~3
  • EP4478939B1 patent drawingFigure 4(a)~4(b)

AI summary

A tissue analysis system and method process hyperspectral images to classify tissue types within the images. A presence or level of tissue oxygenation is estimated for each tissue type as well as a PPG perfusion. The estimated tissue oxygenation and PPG perfusion information are combined to provide a tissue status for each tissue type. The system and method uses remote PPG sensing.