NO Supply Installation With Stored Flows for Sensor Failure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing NO supply installations fail to accurately determine and maintain the required NO flow when the flow sensor malfunctions, leading to unsafe fluctuations in NO content in the gaseous mixture supplied to patients, especially in medical ventilator systems.
Innovation Solution
An NO supply installation with a dual gas circuit system, including a main and secondary flow control mechanism, where the control means determine and store set gas flows before a flow sensor malfunction, allowing the system to switch to an emergency mode and maintain the required NO flow using stored data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a flow sensor is used to measure respiratory gas flow continuously, then the NO flow can be controlled accurately under normal conditions, but the system becomes vulnerable to safety risks when the flow sensor malfunctions or transmission is interrupted
Solution Approach 1:
The control means determine and store the set NO flow in advance based on previously received flow measurements before a malfunction occurs. When the flow sensor transmission is interrupted, the system continues to supply NO at the previously determined set flow rather than stopping or using a fixed predetermined flow, ensuring continuous accurate dosing without requiring real-time flow measurements during emergency mode
Solution Approach 2:
The system prepares for potential sensor failure by establishing an emergency supply mode that relies on stored flow information. This cushioning mechanism ensures that a single point of failure (flow sensor) does not compromise patient safety, as the system can maintain accurate NO dosing using the last known good set flow value
2Reliability
If a fixed predetermined flow of NO/N2 mixture is supplied in emergency mode, then the system can operate without flow measurements, but the NO content of the combined gaseous mixture fluctuates substantially
Solution Approach 1:
Instead of using a fixed predetermined emergency flow, the system determines and stores the specific set NO flow based on actual flow measurements taken before the malfunction. This preliminary calculation of the appropriate set flow ensures that when emergency mode activates, the system supplies the correct variable flow value that was determined based on the patient's actual respiratory needs at that time
Solution Approach 2:
The emergency supply mode uses a dynamic set flow value that was determined based on real flow measurements, rather than a static predetermined flow. This allows the system to adapt to varying respiratory conditions while in emergency mode, maintaining stable NO content in the combined gaseous mixture by supplying the appropriate flow value that corresponds to the patient's actual respiratory gas flow
Data Source
AI summary
The invention concerns an installation (100) to supply a gaseous mixture containing NO comprising an NO supply apparatus (1) connected to a respiratory circuit (20; 21) with an injection device (24) and a flow sensor (25) in order to measure the flow of respiratory gas. The NO supply apparatus (1) comprises a gas circuit (200) with flow control means (220, 221) in order to control the flow of gas in the internal gas circuit (200), and control means (210) in order to determine a set gas flow containing NO, and to control the flow control means (220, 221); and storage means (212) in order to store successive set flows. In the case of interruption of transmission of the flow measurements carried out by the flow sensor (25), the control means (210) control the flow control means (220, 221) in order to supply the gas to an emergency flow calculated from stored set flows.