Miniature Gas Sensor Capsule for Gastrointestinal Diagnostics

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Solution Overview

Problem

Current gas sensors for the gastrointestinal tract are non-selective, leading to inaccurate measurements due to sensitivity to multiple gas species, and existing technologies are too large for human use, limiting their application in diagnosing gastrointestinal illnesses.

Innovation Solution

Development of a small, semi-conducting and thermal conductive gas sensor capsule with a microprocessor-controlled heating mechanism and selectively permeable membranes, allowing for precise temperature-dependent gas detection and differentiation using neural network software, enabling accurate identification of gas species throughout the gastrointestinal tract.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If optical gas sensors (infrared) are used for gas detection, then gas selectivity is improved, but capsule size becomes too large for human use

Engineering Contradiction:
Improvegas selectivityVSAvoidcapsule size
Core Design Contradiction:
Measurement precisionVSVolume of moving object

Solution Approach 1:

The patent replaces optical (infrared) gas sensors with electrochemical gas sensors that utilize electrical fields and chemical reactions instead of optical mechanisms. This substitution enables miniaturization of the sensor and capsule while maintaining gas detection capability, directly resolving the contradiction between gas selectivity and capsule size for human use

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the detection parameter from optical absorption to electrochemical reaction characteristics. By using electrochemical sensors that measure electrical properties (current, voltage) resulting from gas-electrode reactions, the system achieves compact size suitable for human capsules while preserving gas identification capability through selective electrochemical responses

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If non-selective gas sensors are used, then device complexity is reduced, but measurement accuracy deteriorates due to sensitivity to multiple gas species

Engineering Contradiction:
Improvesensor structureVSAvoidgas measurement accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent divides gas detection into multiple independent electrochemical sensor elements, each designed to be selective for specific gas species (e.g., hydrogen, methane, carbon dioxide). By segmenting the detection function across multiple specialized sensors rather than using a single non-selective sensor, the system achieves high measurement accuracy while maintaining relatively simple individual sensor structures

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces selective gas-permeable membranes as intermediaries between the gastrointestinal environment and the electrochemical sensors. These membranes act as filters that allow only specific gas species to reach the sensor electrodes, thereby enhancing measurement accuracy without requiring complex sensor structures

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If gas-permeable membranes are used for selectivity, then gas species differentiation is improved, but sensor response time increases

Engineering Contradiction:
Improvegas species selectivityVSAvoidsensor response time
Core Design Contradiction:
Measurement precisionVSSpeed

Solution Approach 1:

The patent applies different gas-permeable membrane materials with varying permeability characteristics to different sensor elements based on their specific detection requirements. Each membrane is locally optimized for its target gas species, allowing selective permeation while minimizing response time delays. This localized optimization resolves the contradiction between selectivity and response speed

Inventive Principle:
Principle #3Local quality

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 capsule provides high selectivity and sensitivity in gas measurements, allowing for non-invasive diagnostics and accurate correlation of gas species with health status, diet, and illnesses, significantly outperforming breath tests in accuracy.

Implementation Method 1

The sensor surfaces are located above a micro heater so that the sensors are heated in a short duration of less than a second to two or more different temperatures

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

The outer surface of this portion of the capsule is composed of a selectively permeable membrane

Methodology Applied
Scientific EffectGas permeation: Permeation

Implementation Method 3

Semi conducting and thermal conductivity sensors are the base of the invention as they both show gas responses that are a strong and repeatable function of their operating temperatures

Methodology Applied
Scientific EffectSemiconductor gas sensing: Conduction (electrical)

Implementation Method 4

Semi conducting and thermal conductivity sensors are the base of the invention as they both show gas responses that are a strong and repeatable function of their operating temperatures

Methodology Applied
Scientific EffectThermal conductivity sensing: Conduction (thermal)

Data Source

PatentEP3497437B1Gas sensor capsule
Publication Date: 2023.03.01 ROYAL MELBOURNE INST OF TECH
  • EP3497437B1 patent drawingFigure 1A
  • EP3497437B1 patent drawingFigure 1B
  • EP3497437B1 patent drawingFigure 2A

AI summary

A capsule adapted to be introduced into the digestive system and gastrointestinal (Gl) tract of a mammal which consists of a capsule shaped container consisting of a wall material capable of being bio compatible with the digestive system and being adapted to protect the electronic and sensor devices contained in the capsule. The capsule contains gas composition sensors operable at several temperature points for a short duration, a temperature sensor, a micro controller, a power source and a wireless transmission device. The capsule wall incorporates gas permeable membranes adjacent said gas sensors. The microprocessor is programmed to receive data signals from the sensors and convert the signals into gas composition and concentration data and temperature data suitable for transmission to an external computing device.