Respiratory Mask Vent Assembly for Variable CO2 Washout
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Solution Overview
Problem
Current respiratory treatment apparatuses for sleep disordered breathing, such as CPAP therapy, face challenges in efficiently venting carbon dioxide from the mask to prevent rebreathing, particularly at lower operating pressures, where fixed vent configurations require increased flow or power adjustments, leading to discomfort and inefficiency.
Innovation Solution
A variable area gas washout vent arrangement is introduced, utilizing gears, radial exhaust revolvers, or spherical diverters with actuators and controllers to dynamically adjust the venting area, allowing for precise control of gas flow and pressure without significant power changes, enhancing comfort and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed vent configuration is used, then the structure is simple, but adequate carbon dioxide washout cannot be achieved at lower operating pressures
Solution Approach 1:
The patent applies the dynamics principle by transitioning from a fixed vent configuration to a variable vent configuration where the vent area can be dynamically adjusted based on operating conditions. The vent area is modified in response to detected breathing patterns, allowing adequate carbon dioxide washout at lower pressures while maintaining simplicity when not needed.
Solution Approach 2:
The patent implements parameter changes by varying the vent area parameter according to operating pressure and breathing phase. The vent area is increased during expiration to enhance carbon dioxide washout effectiveness and decreased during inspiration to maintain positive pressure, thereby resolving the contradiction between washout effectiveness and structural simplicity.
2Reliability
If vent area is increased to improve carbon dioxide washout, then washout effectiveness improves, but turbulence and noise increase
Solution Approach 1:
The patent applies periodic action by varying the vent area in synchronization with the patient's breathing cycle. The vent area is increased during the expiration phase to enhance carbon dioxide washout and decreased during the inspiration phase to minimize turbulence and noise. This periodic modulation allows effective washout while reducing harmful turbulence and noise effects.
3Productivity
If fixed vent size is used, then device simplicity is maintained, but equipment size and cost must be larger to compensate for inefficiency
Solution Approach 1:
The patent implements dynamics by using a variable vent arrangement that adapts its opening size based on real-time breathing detection. This dynamic adjustment improves gas washout efficiency by optimizing the vent area for each breathing phase, while the overall device complexity remains manageable through the use of a detection system and controllable vent mechanism.
4Reliability
If vent area is increased to maintain washout at lower pressures, then washout is adequate, but positive pressure delivery to patient is reduced
Solution Approach 1:
The patent applies periodic action by synchronizing vent area changes with the breathing cycle phases. During expiration, the vent area is increased to enhance carbon dioxide washout effectiveness. During inspiration, the vent area is decreased to maintain adequate positive pressure delivery to the patient. This periodic modulation resolves the contradiction between washout effectiveness and pressure maintenance.
Solution Approach 2:
The patent implements preliminary action by detecting the breathing phase in advance and adjusting the vent area accordingly. The system detects the transition to expiration phase and increases the vent area proactively to ensure adequate carbon dioxide washout, while detecting the transition to inspiration phase and decreasing the vent area to maintain positive pressure delivery.
Data Source
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AI summary
The present invention relates to an apparatus for automated control of gas washout of a patient interface of a respiratory treatment apparatus comprising a vent assembly having a variable exhaust area. The vent assembly is associated with a patient interface to vent expiratory gas. The vent assembly includes a first gear having a first flow bore; and an actuator to manipulate orientation of the flow bore of the first gear to vary the exhaust area.