Ventilation Gas Identification via Flow Meter Calibration
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Solution Overview
Problem
Existing patient ventilation systems lack adequate safety in identifying the correct gas or gas mixture connected to the system, leading to potential human errors and uncertainty about the gas composition delivered to patients, especially when using mixtures like heliox, which can result in incorrect flow meter calibration and inadequate safety controls.
Innovation Solution
The system employs gas identification means, such as ultrasonic transducers measuring speed of sound or heated thermistors measuring thermal conductivity, to automatically identify gases or gas mixtures and correct flow meter calibrations in real-time, generating alarms for incorrect connections and utilizing existing components like flow meters with transit time technology for simultaneous identification and calibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If gas identification means are added to the ventilation system, then safety and reliability of gas delivery is improved, but device complexity increases
Solution Approach 1:
The patent makes existing flow meters multi-functional by enabling them to perform both flow measurement and gas identification. The flow meters are equipped with sensors (acoustic, thermal, or mass spectrometry) that allow them to detect gas composition while maintaining their primary flow measurement function, thereby improving reliability without adding separate dedicated identification devices
Solution Approach 2:
The system uses its own existing infrastructure (flow meters and gas pathways) to perform gas identification. The flow meters self-identify the gas type by analyzing properties of the gas flowing through them, eliminating the need for external or separate identification systems
2Measurement precision
If flow meters are calibrated for different gas types, then measurement precision is improved, but device complexity and operational complexity increase
Solution Approach 1:
The system dynamically adapts flow meter calibration based on the detected gas composition. When gas identification means detect a change in gas type (e.g., from air to heliox), the system automatically adjusts the flow meter calibration parameters accordingly, eliminating the need for manual recalibration and maintaining measurement precision across different gas types
Solution Approach 2:
The system implements a feedback loop where gas identification results are used to automatically adjust flow meter calibration. The detected gas composition feeds back to the control system, which then modifies the flow measurement parameters to match the specific gas properties, ensuring continuous measurement accuracy without manual intervention
3Ease of operation
If manual gas identification is used, then ease of operation is maintained, but reliability and safety are insufficient
Solution Approach 1:
The system automatically identifies gases using sensors integrated in the flow meters or separate gas identification means. This self-identification eliminates the need for manual checking while providing reliable, objective gas verification through acoustic, thermal, or mass spectrometry-based detection of gas composition
Solution Approach 2:
The gas identification system provides automatic feedback to the user interface, displaying the detected gas type to confirm correct connection. This feedback mechanism maintains operational simplicity by automatically informing users of gas identity without requiring manual verification steps
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 approach enhances safety by ensuring accurate gas identification and automatic flow regulation, reducing vulnerability to human errors and allowing operation with arbitrary gas mixtures, including expensive gases like Zenon in rebreathing setups, while minimizing additional components and providing user feedback.
Implementation Method 1
gas identification means, such as ultrasonic transducers measuring speed of sound
Implementation Method 2
heated thermistors measuring thermal conductivity
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The present invention relates to a patient ventilation system comprising flow regulating and gas mixing means (3, 4, 5, 6) connected to an inspiratory channel (7) of the system wherefrom a gas mixture comprising oxygen and at least a second gas is delivered to the system's proximal tubing (8), which proximal tubing further is connected to an expiratory channel (9) and connectable to a patient, said system further comprises at least two gas inlets (1, 2) connected to said flow regulating and mixing means (3, 4, 5, 6), and gas identification means (10, 10a, 10b) by which said at least second gas supplied to the system via one of said gas inlets (2) can be ident ified. By actively measure a value that is dependent of the characteristics of the delivered gas, and by correcting the calibration of the flow regulating and gas mixing means and/or the flow meter(s) based on this value, both safety and flow regulation in the system is greatly enhanced.