Ventilator Exhalation Flow Valve with Magneto-Mechanical Actuator
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Solution Overview
Problem
Ventilators face challenges in maintaining precise control over exhalation pressure and flow rates, particularly in scenarios where patient inspiratory flow exceeds the bias flow, which can lead to inadequate pressure maintenance and inefficient gas management.
Innovation Solution
A software-controlled exhalation valve system utilizing a magneto-mechanical actuator with a force coil and feedback coil, adjusted by a processor to maintain set pressure levels and target bias flow rates, ensuring accurate control of the valve orifice opening based on real-time pressure and position data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional exhalation valve is used, then the structure is simple, but the control precision over exhalation pressure and flow rates is insufficient
Solution Approach 1:
The patent implements a feedback control system where a sensor detects the actual exhalation pressure and flow rate, and this information is fed back to the controller which adjusts the force coil current accordingly. This closed-loop feedback mechanism enables precise control of exhalation parameters while maintaining a relatively simple valve structure.
Solution Approach 2:
The patent replaces traditional mechanical valve actuation with an electromagnetic force coil system. The force coil generates electromagnetic force to actuate the valve, allowing for precise electronic control of valve opening and flow rates, thereby improving control precision without significantly complicating the overall valve structure.
2Reliability
If the bias flow rate is increased to meet patient inspiratory demand, then the pressure maintenance is improved, but the gas management efficiency deteriorates
Solution Approach 1:
The patent employs a dynamic control system where the exhalation valve opening and force coil current are continuously adjusted based on real-time patient inspiratory demand detection. When patient demand exceeds bias flow, the system dynamically increases valve opening to maintain pressure; when demand is lower, it reduces opening to optimize gas management efficiency. This dynamic adaptation resolves the contradiction between pressure maintenance and gas efficiency.
Solution Approach 2:
The system changes operational parameters (valve opening degree, force coil current, bias flow rate) in real-time based on patient demand. By dynamically adjusting these parameters rather than maintaining a fixed high bias flow, the system achieves reliable pressure maintenance while minimizing energy loss and improving gas management efficiency.
3Speed
If the force coil is moved rapidly to adjust valve opening, then the response speed is improved, but the control stability deteriorates
Solution Approach 1:
The patent employs periodic or pulsed actuation of the force coil rather than continuous rapid movement. The controller applies current in controlled pulses that move the force coil to the desired position, then maintains it there with minimal oscillation. This periodic action approach achieves fast response while maintaining control stability by avoiding continuous high-frequency adjustments.
Solution Approach 2:
The feedback control system monitors the force coil position and valve opening state, adjusting the current in real-time to achieve the desired opening quickly while damping any oscillations. The feedback mechanism ensures that rapid movements are corrected promptly, maintaining control stability even during fast response transitions.
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 solution enables precise control over exhalation pressure and flow rates, ensuring consistent and efficient gas management, even during increased patient inspiratory demands, thereby improving ventilator performance and patient care.
Implementation Method 1
a force coil configured to be moved within a fixed magnetic field in response to a low frequency current
Implementation Method 2
a feedback coil configured to detect the high frequency current in the force coil, the detected high frequency current having a magnitude that is proportional to a force coil position within the fixed magnetic field
Implementation Method 3
a current amplifier configured to direct a summed low frequency current and a high frequency current into the force coil
Data Source
AI summary
Described herein is an exhalation valve for a ventilator that controls gas flow through a patient exhalation line in response to a target pressure within the line. The valve controls gas flow by (i) providing both a high frequency signal and a low frequency signal through a coil positioned in a fixed magnetic field, (ii) determining a position of the coil by detecting the high frequency signal, and (iii) controlling a position of the coil by adjusting the low frequency signal.