Continuous Integrated Sleep Score Using Oximetry and Capnography
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Solution Overview
Problem
Current methods for diagnosing sleep disorders, particularly obstructive sleep apnea (OSA), rely on inadequate parameters such as equal weighting of apnea and hypopnea events, indirect measurement of tidal volumes, and cumbersome sensor interfaces, leading to errors in sleep quality assessment and severity determination.
Innovation Solution
A method and system utilizing a pulse oximeter for continuous oxygen saturation monitoring and a capnograph for exhaled CO2 values to compute a continuous integrated sleep score, assigning weights to events based on oxygen saturation and CO2 values, providing a more accurate and absolute measure of breathing-related sleep quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If equal weighting is applied to all apnea and hypopnea events, then the diagnostic process is simplified, but the measurement precision of sleep quality assessment deteriorates
Solution Approach 1:
The patent applies local quality by assigning different weights to different types of breathing events (apnea, hypopnea, respiratory effort-related arousals) based on their clinical significance. Each event type receives a specific weight value that reflects its impact on sleep quality, allowing the system to differentiate between minor and severe breathing disturbances rather than treating all events equally.
Solution Approach 2:
The patent changes the parameter of event weighting from a uniform value to a variable parameter system. The weighting function incorporates multiple parameters including event type, duration, oxygen desaturation level, and arousal occurrence, transforming the single-parameter count-based approach into a multi-parameter integrated scoring system that dynamically adjusts weights based on event characteristics.
2Device complexity
If indirect measurement methods are used for tidal volumes, then the device complexity is reduced, but the measurement precision of breathing effectiveness deteriorates
Solution Approach 1:
The patent uses oxygen saturation and exhaled CO2 levels as intermediary parameters to indirectly measure breathing effectiveness. Instead of directly measuring tidal volumes, the system monitors oxygen desaturation during apnea events and CO2 levels during hypopnea events, using these physiological markers as mediators to assess the impact of breathing disturbances on sleep quality.
3Ease of operation
If simple event counting is used for sleep disorder diagnosis, then the ease of operation is improved, but the reliability of diagnosis deteriorates
Solution Approach 1:
The patent segments the diagnostic process into distinct event detection and scoring phases. The system automatically detects and categorizes different breathing events (apnea, hypopnea, RERA), assigns weights based on event characteristics, and integrates these weighted scores to generate an overall sleep quality assessment. This segmentation allows the system to maintain operational simplicity while incorporating complex diagnostic criteria through automated algorithms.
4Measurement precision
If comprehensive parameters are monitored for sleep analysis, then the measurement precision is improved, but the device complexity increases
Solution Approach 1:
The patent implements a multi-functional monitoring system that uses a single integrated platform to detect and analyze multiple breathing event types (apnea, hypopnea, RERA) simultaneously. The same sensor array and processing system handle diverse measurement tasks including oxygen saturation monitoring, CO2 level detection, flow rate measurement, and arousal detection, eliminating the need for separate specialized devices for each parameter and reducing overall system complexity.
Data Source
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AI summary
A system for automatic sleep test analysis, the system comprising: a pulse oximeter for continuously monitoring oxygen saturation values of a patient; a capnograph for continuously monitoring exhaled carbon dioxide (C02) values of the patient; and a computing unit configured to compute a continuous integrated sleep score based on a sequential analysis of the oxygen saturation values and the exhaled C02 values, wherein the continuous integrated sleep score is indicative of the patient's breathing-related sleep quality during at least a portion of the sleep test.