Pressurized Tissue Photometry for Disease State Estimation

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Solution Overview

Problem

Existing medical photometers are limited in their ability to accurately estimate both the physiological and disease states of a living tissue, particularly in conditions like sepsis, intraperitoneal bleeding, edema, and vascular endothelium function, without providing comprehensive diagnostic insights.

Innovation Solution

A medical photometer system comprising a photo emitter, detector, pressurization device, and processor that uses light beams of specific wavelengths to analyze tissue changes under controlled pressure conditions, calculating correlation values from light intensity variations to estimate physiological and disease states, and providing visual, audible, or haptic notifications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional photometry is used to measure light transmission through tissue, then the measurement can be performed non-invasively, but the measurement precision is insufficient to accurately estimate both physiological and disease states

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

Solution Approach 1:

The measurement process is segmented into multiple phases: pressurization phase, depressurization phase, and measurement phase. During pressurization, blood flow is restricted to eliminate confounding factors; during depressurization, blood flow resumes allowing tissue perfusion assessment. This temporal segmentation enables separate measurement of different physiological parameters, improving precision without requiring multiple separate devices.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically adjusts the pressurization state of the tissue during measurement. By controlling the pressurization device to alternately apply and release pressure, the system creates dynamic changes in blood flow that can be used to distinguish between different tissue states. This dynamic approach allows a single photometer to assess both perfusion and tissue characteristics, enhancing measurement precision.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If multiple wavelength light beams are used to improve estimation accuracy, then the physiological and disease state estimation improves, but the device complexity increases

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

Solution Approach 1:

The photometer is designed with multi-functionality to perform both physiological state monitoring and disease state detection using the same hardware platform. By combining pressurization control with photometric measurements at multiple wavelengths, the device can assess tissue perfusion, oxygenation, and various disease states (sepsis, edema, intraperitoneal bleeding) without requiring separate specialized devices for each function.

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

Solution Approach 2:

The system utilizes multiple light wavelengths with different penetration depths and tissue interaction characteristics. By measuring light transmission at these different wavelengths during pressurization and depressurization cycles, the system extracts multiple parameters including tissue oxygenation, blood flow, and perfusion characteristics. This parameter diversity enables comprehensive physiological and disease state assessment using a single device.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If pressurization is applied to the tissue to improve measurement accuracy, then the estimation of physiological and disease states improves, but the device complexity increases

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

Solution Approach 1:

The photometer merges the pressurization control function with the photometric measurement function into a single integrated system. The pressurization device and photometer work in coordinated fashion, with the pressurization cycles providing the mechanical stimulus and the photometer providing the optical measurement, combining two functions into one unified diagnostic system that improves accuracy without proportionally increasing complexity.

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

Enables accurate estimation of physiological and disease states such as sepsis, intraperitoneal bleeding, edema, and vascular endothelium function by analyzing light transmission and reflection changes under pressure, offering timely diagnostic feedback.

Implementation Method 1

The living tissue of the subject is irradiated with light beams respectively having a plurality of wavelengths

Methodology Applied
Scientific EffectLight transmission: Light

Implementation Method 2

The quantities of the light beams of the respective wavelengths that are transmitted through or reflected from the living tissue are subjected to detection

Methodology Applied
Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 3

The quantities of the light beams of the respective wavelengths that are transmitted through or reflected from the living tissue are subjected to detection

Methodology Applied
Scientific EffectLight detection: Photoelectric Effect

Implementation Method 4

a pressurization device and a processor, wherein the processor is configured to acquire at least one feature quantity from a temporal change of the signal S1 due to a pressurizing operation performed by the pressurization device

Methodology Applied
Scientific EffectPressure application: Pressure Increase

Data Source

PatentEP3993696B1Medical photometer
Publication Date: 2025.11.12 NIHON KOHDEN CORP
  • EP3993696B1 patent drawingFigure 1
  • EP3993696B1 patent drawingFigure 2A~2B
  • EP3993696B1 patent drawingFigure 3

AI summary

An input interface (41) is configured to receive a signal (S1) corresponding to a quantity of light that has passed through a living tissue of a subject. A pressurization controller (44) is configured to control a pressurizing operation performed with a pressurization device (30) attached to a body of the subject, thereby changing at least one of a thickness of the living tissue, an amount of blood contained in the living tissue, an amount of cellular interstitial fluid contained in the living tissue, an amount of blood flowing into the living tissue, and an amount of blood flowing out from the living tissue. A processor (43) is configured to acquire, from a temporal change of the signal (S1) due to the pressurizing operation, a feature quantity that is used for estimating at least one of a physiological state of the living tissue and a disease state of the subject.