Trunk-Mounted Accelerometer System for Sleep Disorder Detection

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Solution Overview

Problem

Existing methods for assessing sleep quality are often costly, complex, and invasive, requiring multiple sensors that can disrupt sleep and provide variable quality signals, limiting their robustness and user acceptability.

Innovation Solution

A compact, user-friendly system utilizing a pair of accelerometers placed on the individual's trunk, optionally combined with a PPG sensor, microphone, and gyroscope, to capture and analyze cardio-respiratory signals, thereby determining cardio-respiratory descriptors such as AHI and respiratory entropy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple sensors (ECG, respiratory plethysmography, naso-oral thermistor) are used to capture cardio-respiratory signals, then measurement precision and reliability are improved, but device complexity and manufacturing cost increase significantly

Engineering Contradiction:
Improvesignal qualityVSAvoidnumber of sensors
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The accelerometer is used to perform multiple functions: capturing respiratory signals through thoracic movement, detecting cardiac activity through body motion, and monitoring sleep position. This multi-functional approach replaces multiple specialized sensors with a single versatile device, reducing system complexity while maintaining measurement capability

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

Solution Approach 2:

The patent replaces traditional mechanical and physiological sensors (ECG electrodes, plethysmography belts, thermistors) with an inertial measurement system using accelerometers. This substitution uses mechanical motion detection to infer physiological parameters, simplifying the hardware while preserving diagnostic information

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

2Measurement precision

If multiple sensors are placed on the individual (torso, fingers, skull), then measurement precision is improved, but ease of operation and user acceptability deteriorate due to complexity of use and disruption of sleep

Engineering Contradiction:
Improvesignal qualityVSAvoiduser acceptability
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent consolidates multiple sensor placements (torso, fingers, skull) into a single device placed on one location of the individual's trunk. This merging eliminates the burden of wearing multiple separate sensors while capturing comprehensive cardio-respiratory data through the accelerometer's ability to detect various physiological movements from a single position

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single accelerometer device performs multiple measurement functions that traditionally required separate sensors and placements, making the system easier to operate and more acceptable to users while maintaining measurement precision

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

3Measurement precision

If traditional sleep analysis methods are used, then diagnostic accuracy is improved, but accessibility and cost-effectiveness deteriorate, limiting availability to non-specialist practitioners

Engineering Contradiction:
Improvediagnostic accuracyVSAvoidcost and accessibility
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent employs inexpensive accelerometer technology instead of expensive medical-grade sensors, creating a cost-effective solution that can be manufactured and distributed widely. This approach sacrifices some of the high-end capabilities of medical equipment while providing sufficient accuracy for screening and monitoring purposes at a fraction of the cost

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

By replacing complex medical sensing systems with simpler inertial measurement technology, the patent reduces manufacturing costs and technical barriers to entry, making sleep analysis accessible to non-specialist practitioners and consumers without requiring specialized medical infrastructure

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

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 system provides a cost-effective, non-invasive, and robust method for evaluating cardio-respiratory sleep health, capable of detecting sleep disorders and improving public health outcomes by making sleep analysis more accessible to non-specialist practitioners.

Implementation Method 1

a pair of accelerometers embedded within the same hardware device placed in a single location of the individual at the level of the individual's trunk

Methodology Applied
Scientific EffectAcceleration: Accelerometer

Implementation Method 2

a photoplethysmography (PPG) sensor, which allows indirect optical measurement of blood oxygenation and heartbeats

Methodology Applied
Scientific EffectPhotoplethysmography: Photoelectric Effect

Data Source

PatentEP3600010B1System for determining a set of at least one cardio-respiratory descriptor of an individual during sleep
Publication Date: 2025.06.18 UNIVERSITE GRENOBLE ALPES
  • EP3600010B1 patent drawingFigure 1~2B
  • EP3600010B1 patent drawingFigure 3

AI summary

The invention relates to a method for detecting a set of events that are potentially indicative of sleep disturbances. The method is essentially characterized by: - Recording (100) beforehand in a data memory o A first accelerometer in a thoracic position, o A second accelerometer, synchronized with the first, in an abdominal position; o A photoplethysmography sensor in a thoracic position; - Filtering (110) said data by extraction o of low-frequency, medium-frequency and high-frequency ranges of the first accelerometer, and o at least one low-frequency range of the second accelerometer, - Determining (120), in at least one range, a set of characteristics that are representative of a cardio-respiratory state, and also their moment of extraction, and - Comparing (130) said set of characteristics with a reference model comprising a correlation between a set of characteristics distributed over time and a set of physiological events, and - Deducing therefrom (140) a set of at least one probable corresponding event that the individual has faced.