Variable Aperture Gas Inlet Seal for Respiratory Flow Control
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Solution Overview
Problem
Existing respiratory treatment apparatuses face challenges in effectively controlling gas flow, particularly in preventing backflow and adjusting inlet flow according to patient needs.
Innovation Solution
A flow control device with a variable inlet aperture and a flexible seal, controlled by a seal activation chamber and electro-mechanical valves, allows for adjustable gas flow, prevents backflow, and optimizes blower operation by unloading it during expiration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed inlet aperture is used in the flow generator, then the device structure is simple, but the gas flow cannot be adjusted according to patient needs
Solution Approach 1:
The patent applies the dynamics principle by implementing a variable inlet aperture that can change its opening size dynamically. The aperture includes a movable seal element that can shift position to adjust the opening area, allowing the gas flow rate to be varied according to patient respiratory needs while maintaining a relatively simple overall device structure.
2Reliability
If the inlet aperture remains open during expiration, then continuous gas supply is maintained, but backflow of breathable gas occurs
Solution Approach 1:
The patent applies preliminary anti-action by using a seal element that proactively closes or reduces the inlet aperture during the expiration phase before significant backflow can occur. The control system detects the expiration phase and actuates the seal to close the aperture in advance, preventing backflow into the flow generator while the patient exhales through the patient interface.
3Loss of energy
If the blower operates continuously to maintain pressure, then stable gas supply is ensured, but energy consumption increases and noise is amplified
Solution Approach 1:
The patent applies periodic action by controlling the blower to operate intermittently rather than continuously. The control system modulates the blower operation based on the respiratory cycle phase and patient flow demands, activating it during inspiration when gas supply is needed and reducing or stopping operation during expiration when demand is lower. This periodic operation reduces energy consumption and noise while maintaining adequate pressure stability through coordinated aperture control.
4Speed
If the inlet aperture closes rapidly to stop flow, then response time is reduced, but pressure fluctuations increase
Solution Approach 1:
The patent applies dynamics by implementing a controlled, dynamic closure mechanism for the inlet aperture. Rather than abrupt closing, the seal element moves gradually to reduce the aperture opening size in a controlled manner. The control system modulates the closure speed and aperture reduction rate to achieve rapid response to changing flow demands while minimizing pressure fluctuations that could disrupt patient breathing or damage system components.
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
The solution enables precise control of gas flow, prevents backflow, reduces noise, and optimizes blower efficiency by allowing rapid start/stop of flow, thus enhancing the effectiveness and comfort of respiratory treatments.
Implementation Method 1
A seal activation chamber is configured proximate to the second side of the inlet flow seal to allow a negative pressure in the seal activation chamber to open the gas inlet to a flow of breathable gas.
Implementation Method 2
The flow generator also includes a pressure communication conduit to connect the interior inlet chamber and the seal activation chamber for pressure communication such that a negative pressure in the interior inlet chamber results in a negative pressure in the seal activation chamber.
Data Source
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Figure 1A
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AI summary
The present invention discloses a flow generator for a respiratory treatment apparatus comprising: a motor; an impeller (105) coupled with the motor; a housing for the impeller comprising a volute, a gas inlet (110) and a gas outlet (106), the gas outlet being adaptable for a conduit of a patient interface to deliver breathable gas as a respiratory treatment; an inlet flow seal (114) positioned to selectively open and close the gas inlet, the inlet flow seal (114) having - a first side internally proximate to an inlet chamber (110) of the gas inlet (108) and the inlet flow seal having - a second side externally proximate to the inlet chamber (110) of the gas inlet (108); and a seal activation chamber (118) configured proximate to the second side of the inlet flow seal to permit a negative pressure in the seal activation chamber to open the gas inlet to a flow of breathable gas.