Radar Breathing Analysis for Contactless Sleep Apnea Classification

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Solution Overview

Problem

Conventional sleep disorder detection methods, such as polysomnography and wrist actigraphy, struggle to differentiate between obstructive sleep apnea (OSA) and central sleep apnea (CSA) and require expensive, intrusive devices for precise examination.

Innovation Solution

A radar-based system that analyzes breathing patterns to classify sleep events, detect sleep disorders, and determine their occurrence times by transmitting and receiving radar signals, deriving average breathing signals, generating feature information, and using prediction models to identify sleep-related symptoms like OSA, CSA, and mixed sleep apnea.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If polysomnography is used to precisely examine sleep diseases, then measurement precision is improved, but device complexity and cost increase

Engineering Contradiction:

Improvesleep disorder detection accuracyVSAvoidtester complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the essential breathing measurement function from complex polysomnography systems. By using radar to specifically measure chest and abdominal breathing movements, the system isolates the critical diagnostic parameter (breathing pattern) without requiring the full suite of polysomnography equipment, thereby reducing device complexity while maintaining diagnostic precision for sleep apnea detection

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces mechanical contact-based sensors (worn testers, electrodes, belts) with radar-based electromagnetic sensing. This substitution eliminates the need for physical contact and complex mechanical sensor arrays, reducing device complexity and improving patient comfort while maintaining the ability to precisely measure breathing movements for sleep disorder diagnosis

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If polysomnography is used to detect sleep disorders, then measurement precision is improved, but ease of operation deteriorates due to intrusive devices

Engineering Contradiction:

Improvesleep event detection accuracyVSAvoidsubject comfort

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The patent introduces radar waves as an intermediary medium to measure breathing patterns without direct contact with the subject. The radar system acts as a mediator that captures breathing information through electromagnetic wave reflection, eliminating the need for intrusive sensors on the subject's body while maintaining measurement precision for detecting sleep events like apnea and hypopnea

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces mechanical contact sensors (chest straps, abdominal belts, skin electrodes) with radar-based electromagnetic sensing. This substitution eliminates physical intrusion into the subject's body, dramatically improving ease of operation and subject comfort while preserving the ability to accurately detect breathing patterns and sleep disorders

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If conventional sleep testing methods are used, then basic sleep quality measurement is achieved, but ability to differentiate OSA and CSA deteriorates

Engineering Contradiction:

Improvesleep quality assessment capabilityVSAvoidapnea type differentiation accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent segments the breathing measurement into distinct components: chest breathing movement and abdominal breathing movement. By separately tracking these two segments and analyzing their relative patterns (e.g., chest-in/abdomen-out for OSA versus coordinated movement for CSA), the system achieves precise differentiation between obstructive and central sleep apnea types, overcoming the limitation of conventional methods that treat breathing as a single unified measurement

Inventive Principle:

Principle #1Segmentation

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, contactless detection and continuous monitoring of sleep disorders, reducing inconvenience and cost compared to traditional methods, and providing accurate differentiation between various sleep apneas without the need for polysomnography.

Implementation Method 1

a transceiver configured to transmit a radar signal toward a subject and receives the radar signal reflected from the subject

Methodology Applied

Scientific EffectRadar: Radar

Data Source

PatentUS12569189B2Device, method and computer program for determining sleep event using radar

Publication Date: 2026.03.10 BITSENSING INC

AI summary

A device for determination of a sleep event using a radar includes a transceiver configured to transmit a radar signal toward a subject and receives the radar signal reflected from the subject; an average breathing signal derivation unit configured to derive an average breathing signal of the subject based on the radar signal; a breathing feature information generation unit configured to compare the radar signal with the average breathing signal and generate breathing feature information of the subject; a prediction information derivation unit configured to derive event occurrence prediction information for a plurality of sleep items based on the breathing feature information; and a sleep event determination unit configured to determine whether a sleep event has occurred in the subject based on the event occurrence prediction information.