Ventilator Reactance Feedback for Alveolar Recruitment

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Solution Overview

Problem

Current methods lack non-invasive and automatic means to quantify alveolar derecruitment and determine optimal positive end-expiratory pressure in patients with respiratory failure, relying on clinical expertise and invasive procedures.

Innovation Solution

A non-invasive system using a mechanical ventilator with additional pressure components and computing means to automatically set and adjust positive end-expiratory pressure based on inspiratory reactance measurements, allowing for real-time monitoring and optimization without interrupting ventilation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If mechanical ventilator with PEEP is used to counteract alveolar derecruitment, then alveolar recruitment is improved, but risk of ventilator-induced lung injury increases due to potential overdistension

Engineering Contradiction:
Improvealveolar recruitmentVSAvoidventilator-induced lung injury
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system continuously monitors inspiratory reactance and uses this feedback to dynamically adjust PEEP levels. The computing means processes reactance measurements in real-time and automatically modifies ventilator settings to maintain optimal alveolar recruitment while preventing overdistension and ventilator-induced lung injury.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces traditional mechanical methods of determining optimal PEEP (such as static pressure-volume curves requiring sedation and paralysis) with a computational approach using inspiratory reactance measurements. This substitution allows for non-invasive, automated optimization of ventilation parameters without requiring patient sedation or paralysis.

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

2Measurement precision

If static pressure-volume curve method is used to identify optimal PEEP, then accurate detection of alveolar recruitment is improved, but patient safety deteriorates due to requirement of sedation, paralysis and apnea

Engineering Contradiction:
Improveoptimal PEEP detectionVSAvoidpatient safety
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces the mechanical static pressure-volume curve method with a computational approach based on inspiratory reactance measurements during spontaneous or assisted breathing. This substitution eliminates the need for sedation, paralysis, and apnea while maintaining accurate detection of optimal PEEP levels through continuous monitoring of respiratory system mechanics.

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

Solution Approach 2:

The system enables continuous monitoring of inspiratory reactance and dynamic adjustment of PEEP throughout the ventilation process, rather than requiring intermittent static measurements that interrupt breathing. This continuous action allows for real-time optimization of alveolar recruitment while maintaining patient safety and spontaneous breathing.

Inventive Principle:
Principle #20Continuity of useful action

3Ease of operation

If PEEP is set based on clinical experience and insight, then ease of operation is improved, but measurement precision of alveolar recruitment deteriorates

Engineering Contradiction:
ImprovePEEP settingVSAvoidalveolar recruitment quantification
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The system performs self-service by automatically measuring inspiratory reactance, computing optimal PEEP levels, and adjusting ventilator settings without requiring continuous clinical intervention or expertise. The computing means autonomously processes respiratory signals and optimizes ventilation parameters, making precise alveolar recruitment management accessible without specialized skill.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces subjective clinical judgment with objective computational analysis of inspiratory reactance. The system uses mathematical processing of respiratory signals to precisely quantify alveolar recruitment and determine optimal PEEP, substituting clinical experience-based estimation with measurement-driven decision making.

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

Data Source

PatentEP2061538B1Apparatus for respiratory support and non-invasive detection of alveolar derecruitment for patients suffering from respiratory failure
Publication Date: 2017.08.23 POLITECNICO DI MILANO
  • EP2061538B1 patent drawingFigure 1
  • EP2061538B1 patent drawingFigure 2~3
  • EP2061538B1 patent drawingFigure 4~6

AI summary

There is described an apparatus (1) for respiratory support and non- invasive detection of alveolar derecruitment for patients suffering from respiratory failure. Such an apparatus (1) generally comprises a mechanical ventilator (3) for inspiration/expiration functions and means (15) allowing to impose an additional periodic pressure component (Pstim) having a higher frequency than the spectral content of the inspiration/expiration pressure component (Presp). There are provided computing means (12) to obtain the inspiratory average reactance (Xrs) of the respiratory system of the patient (2) as the positive end-expiratory pressure (PEEP) varies, in order to detect the presence of alveolar derecruitment. There is also described a procedure allowing to obtain an optimal positive end-expiratory pressure.