Adaptive PEEP Regulation via Real-Time Exhalation Measurement
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Solution Overview
Problem
Prior ventilators fail to adaptively control expiratory gas flow during exhalation, leading to air trapping and increased carbon dioxide accumulation due to delayed and attenuated pneumatic effects from long gas paths, which cannot detect or prevent residual lung volume issues during spontaneous ventilation.
Innovation Solution
A method and device that directly measure and adjust exhalation parameters at the ventilator's user interface, using an exhalation valve to change positive end-expiratory pressure (PEEP) based on real-time resistance and flow measurements, allowing for adaptive control of expiratory flow to prevent air trapping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If PEEP is set by means of an exhalation valve with long gas paths, then the valve can be positioned away from the patient, but the measurement of exhalation parameters is delayed and attenuated
Solution Approach 1:
The patent extracts the measurement function from the distant exhalation valve location and places it directly at the patient interface. A separate measurement device is positioned at the patient connection point to directly measure exhalation parameters, eliminating the need to transmit pneumatic signals through long gas paths while maintaining the ability to position the main valve remotely.
Solution Approach 2:
The patent introduces an intermediary measurement device at the patient interface that acts as a mediator between the patient's lungs and the control system. This intermediary directly senses exhalation parameters and transmits this information to the control unit, bypassing the delays caused by long gas paths in the pneumatic system.
2Reliability
If PEEP is increased to prevent lung collapse, then lung support is improved, but air trapping and carbon dioxide accumulation occur
Solution Approach 1:
The patent implements feedback control by continuously monitoring exhalation parameters such as exhalation flow and resistance, and using this information to dynamically adjust PEEP settings. The control unit processes the measured data and modifies the PEEP level in real-time to prevent both lung collapse and air trapping, maintaining optimal lung support without causing harmful effects.
Solution Approach 2:
The patent transitions from static PEEP settings to dynamic, adaptive PEEP regulation. The system continuously adjusts PEEP based on real-time measurement of exhalation parameters, allowing the PEEP level to change dynamically during the exhalation phase and across different breathing cycles to match the patient's actual respiratory needs and prevent air trapping.
3Device complexity
If the exhalation valve is positioned away from the patient, then the gas path is longer, but the device structure is simpler
Solution Approach 1:
The patent extracts the measurement function from the distant valve location and places it directly at the patient interface. A separate measurement device is positioned at the patient connection point to directly measure exhalation parameters, eliminating the need to transmit pneumatic signals through long gas paths while maintaining the ability to position the main valve remotely.
Solution Approach 2:
The patent replaces the mechanical pneumatic signal transmission through long gas paths with an electronic measurement and control system. The measurement device at the patient interface electronically transmits exhalation parameter data to the control unit, substituting the delayed pneumatic feedback mechanism with rapid electronic sensing and processing.
Data Source
AI summary
A method controls an expiratory gas flow at a user interface (16) of a ventilator (1) wherein the user interface (16) has an exhalation valve (11), which provides a positive end-expiratory pressure (PEEP). The method includes the following steps during a phase of exhalation: changing the positive end-expiratory pressure from a basic PEEP value (31) with the exhalation valve (11); returning the positive end-expiratory pressure to the basic PEEP value (31) with the exhalation valve (11); and determining an exhalation parameter. The method permits an adaptive change in the expiratory flow during the exhalation. Air trapping can be avoided, and it is possible to respond to changed exhalation parameters within one and the same phase of exhalation.