Ventilator Exhalation Valve Bypass for Accurate PEEP Pressure Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing expiration valve arrangements in respiration devices face challenges in accurately measuring respiratory gas pressure upstream of the valve assembly due to structural limitations, making it difficult to set positive end-expiratory pressure (PEEP) precisely, as the pressure measurement at the proximal end of the expiration line is not meaningful for the distal end region due to hose elasticity and radial chamber design.
Innovation Solution
Incorporating a bypass chamber that communicates fluidically with the upstream respiratory gas channel and extends into the downstream channel, allowing for easy access and coupling of a gas pressure sensor to measure the pressure upstream of the valve assembly, with a closure membrane that can be quickly pierced for metrological coupling, ensuring accurate pressure detection and minimizing the risk of component detachment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If pressure measurement is taken at the proximal end of the expiration line, then measurement setup is simple, but measurement precision is insufficient due to hose elasticity and radial chamber design
Solution Approach 1:
A bypass channel is introduced as an intermediary fluidic pathway that connects the upstream respiratory gas channel to the downstream channel. This bypass channel serves as a mediator to transmit pressure information from the distal region (near the valve assembly) to a location where sensors can be accurately positioned, eliminating the need to measure directly in the elastic proximal hose while still capturing the relevant pressure data for PEEP setting.
2Measurement precision
If a bypass chamber is added to enable accurate pressure measurement, then measurement precision improves, but device complexity increases
Solution Approach 1:
The bypass chamber is merged with the existing downstream respiratory gas channel, forming an integrated structure rather than a separate component. The bypass channel is formed as part of the valve body or channel assembly, combining the flow path and pressure measurement functions within a single structural element, thereby minimizing the increase in device complexity.
Solution Approach 2:
The bypass channel serves multiple functions: it acts as a fluidic pathway for respiratory gas flow, provides a pressure equalization path, and creates a accessible location for pressure sensor placement. This multi-functionality reduces the need for additional separate components, offsetting the complexity increase by consolidating multiple functions into a single structural feature.
3Ease of operation
If closure membrane is made pierceable for quick sensor coupling, then ease of operation improves, but reliability decreases due to potential sealing issues
Solution Approach 1:
A closure membrane made of flexible material is used to seal the sensor coupling opening. This thin film structure allows for easy puncturing with a needle or probe to establish fluidic connection with the bypass channel, while the flexibility of the material enables it to conform to the puncture opening and maintain sealing when not in use, balancing ease of operation with sealing reliability.
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
Enables precise detection of respiratory gas pressure upstream of the valve assembly, facilitating the setting of PEEP and ensuring operational reliability by allowing for quick setup and accurate measurement of gas pressure, reducing the risk of component detachment and ensuring sealing integrity.
Implementation Method 1
a bypass chamber (74) that communicates fluidically with the upstream respiratory gas channel (54) and extends from the upstream respiratory gas channel (54) into the region of the downstream respiratory gas channel (58)
Implementation Method 2
allowing for easy access and coupling of a gas pressure sensor to measure the pressure upstream of the valve assembly
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An exhalation valve device (22) for a ventilator apparatus for the artificial respiration of patients can be flowed through in an exhalation flow direction (E) and comprises: - an upstream breathing gas duct (54), which extends along a first duct path (K1) and is or can be connected to a section of the exhalation line coming from the patient, - a downstream breathing gas duct (58), which extends along a second duct path (K2) and is or can be connected to a breathing gas sink (U), - a valve assembly (63) having a valve body (64) and a valve seat (66), which valve assembly is provided between the upstream and the downstream breathing gas ducts (54, 58) such that, in the event of a predetermined first breathing gas overpressure in the upstream gas duct (54) relative to the downstream gas duct (58), said valve assembly permits an exhalatory breathing gas flow from the upstream breathing gas duct (54) to the downstream breathing gas duct (58) and, in the event of a predetermined second breathing gas overpressure in the downstream breathing gas duct (58) relative to the upstream breathing gas duct (54), said valve assembly blocks a gas flow from the downstream breathing gas duct (58) to the upstream breathing gas duct (54). According to the invention, the exhalation valve arrangement (22) has a bypass chamber (74) that communicates via flow mechanics with the upstream breathing gas duct (54) and extends from the upstream breathing gas duct (54) to the region of the downstream breathing gas duct (58) and there is designed for coupling a gas pressure sensor (80).