Automatic Therapeutic EPAP Titration Using Expiratory Time Constants

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Solution Overview

Problem

Traditional methods for detecting airway collapse during bilevel pressure therapy in Obstructive Sleep Apnea patients are inadequate, as they rely on inspiratory flow limitations, which are not applicable when inspiratory pressure is higher than expiratory pressure, and mechanical ventilators prevent extended apneic intervals, necessitating a new approach to detect and treat airway collapse during expiration.

Innovation Solution

The method involves tracking the expiratory time constant to determine therapeutic expiratory positive airway pressure (EPAP) dosage by analyzing breath data and adjusting pressure using algorithms to stabilize the airway with minimal pressure, incorporating expiratory time constant measurements and flow patterns to optimize EPAP dosage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional inspiratory flow limitation methods are used to detect airway collapse, then airway collapse can be detected in standard CPAP therapy, but these methods fail in bilevel pressure therapy where inspiratory pressure is higher than expiratory pressure

Engineering Contradiction:

Improveairway collapse detection accuracyVSAvoidapplicability to bilevel pressure therapy

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent inverts the traditional approach by detecting airway collapse during expiration rather than inspiration. Instead of using inspiratory flow limitation as the detection criterion, the system monitors expiratory flow patterns and expiratory time constants to identify airway collapse events, making the detection method applicable to bilevel pressure therapy where inspiratory pressure exceeds expiratory pressure

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent changes the detection parameter from inspiratory flow characteristics to expiratory flow characteristics and expiratory time constants. By monitoring changes in expiratory flow patterns and calculating expiratory time constants during different EPAP levels, the system achieves accurate airway collapse detection in bilevel pressure therapy conditions

Inventive Principle:

Principle #35Parameter changes

2Reliability

If mechanical ventilator backup breath rate is used to prevent apnea, then extended apneic intervals are prevented, but the ability to detect airway collapse during extended apneic intervals is lost

Engineering Contradiction:

Improveapnea preventionVSAvoidairway collapse detection during apnea

Core Design Contradiction:

ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent performs preliminary detection of airway collapse by monitoring expiratory flow patterns and expiratory time constants before extended apnea occurs. The system identifies trends in expiratory parameters that precede apneic events, allowing early detection and intervention while the ventilator's backup breath rate is still preventing full apnea

Inventive Principle:

Principle #10Preliminary action

3Stability of the object's composition

If higher EPAP dosage is applied to stabilize airway, then airway stability improves, but patient discomfort increases

Engineering Contradiction:

Improveairway stabilityVSAvoidpatient discomfort

Core Design Contradiction:

Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The patent implements a feedback mechanism that continuously monitors expiratory flow patterns and expiratory time constants to dynamically adjust EPAP dosage. The system identifies the minimum EPAP level that achieves airway stability by detecting when expiratory time constants indicate resolved airway collapse, thereby avoiding excessive pressure and patient discomfort while maintaining therapeutic effectiveness

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS12447296B1Systems and methods of determining therapeutic expiratory pressure automatically

Publication Date: 2025.10.21 BREAS MEDICAL AB

AI summary

A system and method for determining therapeutic expiratory positive airway pressure (EPAP) dosage through constant monitoring of flow patterns, which can be used to determine the expiratory time constant, and upon determining the expiratory time constant comparing that we various EPAP dosages to determine an optimal therapeutic EPAP dosage.