NO Delivery Control for HFO Ventilators Without Flow Sensors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing NO delivery systems face inaccuracies when used with high-frequency oscillation (HFO) ventilators due to pressure swings causing false flow readings by internal flow sensors, leading to inaccurate NO dosing.
Innovation Solution
A gas delivery system for HFO ventilators that uses a solenoid valve controlled by a control unit, without an internal flow sensor in the NO injection line, utilizing a respiratory gas flow sensor and differential pressure sensor to determine actual flow and deliver NO in pulses based on measured pressure differentials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If an internal flow sensor is used in the NO injection line to measure therapeutic gas flow, then real-time NO dosing control is improved, but measurement precision deteriorates due to false flow readings caused by HFO pressure swings
Solution Approach 1:
The patent removes the internal flow sensor from the NO injection line, extracting the problematic measurement component that caused false readings during HFO ventilation. Instead, the system uses a proportional valve controlled by a microprocessor that calculates required NO flow based on patient parameters and posology, eliminating the source of measurement error while maintaining automated dosing control.
2Productivity
If pressure swings are allowed to occur during HFO ventilation to deliver tidal volumes, then ventilation effectiveness is improved, but device complexity increases due to the need for filtering and interpolating flow measurements
Solution Approach 1:
The patent eliminates the complex flow measurement processing by removing the internal flow sensor entirely. The system replaces sensor-based measurement with microprocessor-based calculation of NO flow requirements, using patient parameters (age, weight, lung function) and posology to determine the exact NO dose needed, thereby avoiding all filtering and interpolation complexities.
Solution Approach 2:
The patent replaces the mechanical flow sensor system with an electronic control system using a proportional valve and microprocessor. Instead of mechanically measuring flow and then processing the data, the system electronically calculates the required NO flow and directly controls the proportional valve to deliver the precise amount, substituting mechanical measurement with electronic control.
3Device complexity
If a proportional valve is used for NO delivery without internal flow sensor, then device complexity is reduced, but measurement precision of actual NO flow deteriorates
Solution Approach 1:
The patent implements a feedback control system where the microprocessor continuously monitors patient parameters and posology requirements, calculates the needed NO flow, adjusts the proportional valve accordingly, and can make real-time adjustments based on patient response. This closed-loop control ensures precise NO delivery without requiring direct flow measurement in the injection line.
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
Accurately delivers NO doses to patients by compensating for pressure variations, enhancing dosing accuracy without the need for internal flow sensors, even with HFO ventilators.
Implementation Method 1
the respiratory gas flow sensor comprises a flow restriction for creating a pressure differential that is measured by a differential pressure sensor connected to the respiratory gas flow sensor
Data Source
Figure 1~2
Figure 3
AI summary
The invention concerns a gas delivery system (1, 2) for providing gaseous NO to a patient comprising a medical ventilator (2) providing a respiratory gas, such as air, to a patient breathing circuit (3) having an inspiratory limb (31) with a flow sensor (100) and an NO injection module (110), and a NO-delivery device (1) for providing a NO-containing gas to the NO injection module (110) of the inspiratory limb (31), said NO delivery device (1) including a control unit (130) and a differential pressure sensor (104). The medical ventilator (2) can be a HFO ventilator.