Regional Lung Compliance Measurement via EIT and Pressure Sensing
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Solution Overview
Problem
Current methods for determining lung extensibility in patients are inadequate, as they fail to accurately measure regional differences within the lungs, leading to potential lung collapse or over-expansion during ventilation, especially when spontaneous breathing interacts with artificial ventilation.
Innovation Solution
An arrangement comprising an EIT measuring device and a respiratory pressure sensor, which calculates regional extensibility by determining volume and pressure differences across distinct lung areas, allowing for precise adjustment of ventilator settings to prevent lung damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If global lung compliance measurement is used, then overall lung extensibility is assessed, but regional differences in lung compliance cannot be detected
Solution Approach 1:
The patent divides the lung into multiple regional zones (e.g., upper, lower, left, right lung regions) and measures compliance independently for each zone using electrical impedance tomography. This segmentation allows detection of regional compliance differences that would be masked by global measurement, directly resolving the contradiction between measurement precision and device complexity by implementing distributed sensing.
Solution Approach 2:
The patent transitions from one-dimensional global compliance measurement to three-dimensional regional compliance mapping by incorporating spatial distribution of electrical impedance changes throughout the lung volume. This dimensional expansion enables regional differentiation while using the same EIT technology platform, effectively resolving the contradiction without proportionally increasing device complexity.
2Reliability
If uniform ventilation pressure is applied, then simple ventilator control is maintained, but regional lung over-expansion or collapse cannot be prevented
Solution Approach 1:
The patent implements a feedback control system where regional compliance measurements from EIT continuously inform ventilator pressure adjustment. The system monitors regional lung response to applied pressure and dynamically modifies ventilation parameters to prevent over-expansion in compliant regions and collapse in stiff regions, resolving the contradiction between reliability and ease of operation through automated closed-loop control.
Solution Approach 2:
The patent transitions from static uniform pressure application to dynamic region-specific pressure modulation. The ventilator adjusts pressure distribution in real-time based on measured regional compliance variations, allowing optimal lung protection without requiring complex manual intervention, thus resolving the contradiction between reliability and operational simplicity.
3Speed
If manual ventilator adjustment is used, then operator control is maintained, but rapid response to changing lung conditions is limited
Solution Approach 1:
The patent implements an automated system where the ventilator independently monitors regional compliance via EIT and self-adjusts ventilation parameters without operator intervention. This self-service capability enables rapid response to changing lung conditions while reducing the burden on operators, resolving the contradiction between response speed and extent of automation through intelligent autonomous control.
Solution Approach 2:
The patent replaces manual mechanical adjustment of ventilator settings with automated electronic control based on real-time EIT measurements. The system uses computational algorithms to process impedance data and automatically modify ventilation parameters, enabling faster response times while minimizing the need for manual intervention, thus resolving the contradiction between speed and automation extent.
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
This solution enables accurate measurement of regional lung extensibility, allowing for optimal ventilator settings that prevent lung collapse and over-expansion, improving patient monitoring and ventilation efficacy.
Implementation Method 1
capable of measuring the volume change of a lung region using an electrical impedance tomography (EIT) method
Implementation Method 2
an airway pressure sensor which is capable of measuring a time-varying pressure at or in the patient's airway
Data Source
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AI summary
The invention relates to an arrangement and a method for determining a measure of the respective regional distensibility of a patient's lung (P) in several different lung regions. An airway pressure sensor (3) measures the time-varying pressure (Paw) at the patient's airway (P). The difference between the end-inspiratory transpulmonary pressure and the end-expiratory transpulmonary pressure is determined. An EIT measuring device (17) measures the volume change of a lung region using electrical impedance tomography (EIT). Using signals from the EIT measuring device (17), the difference between the end-inspiratory and end-expiratory volumes of the lung region is determined. The quotient of the volume difference for this region and the pressure difference applied to the lung is calculated as a measure of the regional distensibility of the lung region.