PPG Signal Abnormal Respiration Detection via Time-Axis Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current technologies lack effective methods for detecting abnormal respiration, such as apnea, using wearable devices, particularly for self-diagnosis in familiar environments, which is crucial for monitoring isolated individuals and improving sleep quality.
Innovation Solution
A wearable device equipped with a photoplethysmography (PPG) sensor, band pass filter, and analog-to-digital converter, which derives respiration rate signals and characteristic values through time-axis analysis to detect abnormal respiration by comparing peak-to-valley values and peak counts against reference values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If wearable devices are used for apnea detection, then portability and ease of use are improved, but measurement precision and reliability are insufficient
Solution Approach 1:
The patent uses PPG signal as an intermediary to indirectly detect respiration patterns. Instead of directly measuring respiration, the system captures blood volume changes through photoplethysmography, which reflects respiratory-induced variations in blood flow. This intermediary approach enables portable detection while maintaining accuracy by leveraging the physiological coupling between respiration and blood volume changes.
Solution Approach 2:
The patent replaces traditional mechanical respiration sensors (such as chest straps or airflow sensors) with optical PPG sensing. This substitution eliminates the need for direct mechanical contact or complex sensor assemblies, enabling wearable form factors while detecting respiration through optical measurement of blood volume changes that correlate with respiratory cycles.
2Measurement precision
If traditional apnea detection methods are used, then measurement precision is maintained, but device complexity and cost increase
Solution Approach 1:
The patent makes the PPG sensor serve multiple functions: it simultaneously measures heart rate, blood oxygen saturation, and respiration patterns. By extracting respiratory information from the same optical signal used for cardiovascular monitoring, the system achieves multi-parameter detection with a single sensor, reducing device complexity while maintaining diagnostic accuracy.
Solution Approach 2:
The patent extracts respiratory information by isolating specific frequency components and signal characteristics from the PPG waveform. Through spectral analysis and identification of respiratory-induced modulations in the blood volume signal, the system separates respiratory data from the composite PPG signal, enabling dedicated respiration detection without adding separate sensing hardware.
3Ease of operation
If self-diagnosis services are provided, then user convenience is improved, but reliability of detection may be compromised
Solution Approach 1:
The patent implements feedback mechanisms where the system continuously monitors PPG signal quality and detects artifacts or motion interference. When signal quality deteriorates or motion is detected, the system can alert the user to remain still or indicate that the measurement is invalid, ensuring reliable data collection while maintaining ease of use through automated quality control.
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 effective detection of abnormal respirations like central, obstructive, and mixed apnea, allowing for self-diagnosis and improved sleep quality, while also monitoring vulnerable populations like isolated elders and soldiers.
Implementation Method 1
a sensor for sensing a photoplethysmography (PPG) signal from an optical signal reflected and received from a user's body
Data Source
AI summary
An abnormal respiration detection apparatus includes a sensor for sensing a PPG signal from an optical signal reflected and received from a user's body; a band pass filter for extracting a signal of a required band from the PPG signal; an analog-to-digital converter for performing a digital conversion on the filtered PPG signal; and an abnormal respiration recognition unit deriving a respiration rate signal from the digital-converted PPG signal, deriving a plurality of respiration rate characteristic values through a time axis analysis on the derived respiration rate signal, and detecting an abnormal respiration using the derived plurality of respiration rate characteristic values. The embodiments can be utilized to monitor the survival of elders who live alone, soldiers isolated in a military operation, persons isolated in disaster and accident sites, thereby contributing to public and social safety and building of welfare society and nation.