CPAP Pressure Control for COPD Airway Collapse Prevention
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Solution Overview
Problem
Patients with COPD diseases, such as emphysema and chronic obstructive bronchitis, experience airway collapse during expiration due to increased intrapulmonary pressure, leading to incomplete ventilation and reduced lung ventilation.
Innovation Solution
A device that gradually lowers inspiratory IPAP pressure to an end-expiratory level, using a combination of steep and slow pressure drops to maintain airway openness during expiration, with adjustable phases and characteristics to optimize exhalation flow and prevent airway collapse.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If IPAP pressure is rapidly lowered to support efficient exhalation, then exhalation efficiency is improved, but airway collapse occurs due to insufficient counter-pressure
Solution Approach 1:
The exhalation phase is divided into multiple distinct phases (first exhalation phase with rapid pressure drop, second exhalation phase with slower pressure drop) to sequentially address different physiological needs: initial efficient gas removal followed by airway support
Solution Approach 2:
The pressure drop characteristic is dynamically adjusted during the exhalation phase, transitioning from a steep initial drop to a slower subsequent drop, allowing the system to adapt to changing airway conditions throughout expiration
2Productivity
If IPAP pressure is lowered to reduce intrapulmonary pressure, then ventilation is improved, but airways collapse during expiration
Solution Approach 1:
The first exhalation phase with rapid pressure drop is applied preliminarily to reduce intrapulmonary pressure and improve ventilation, followed by the second phase that prevents the harmful effect of airway collapse
Solution Approach 2:
The pressure control follows a periodic pattern during expiration, alternating between rapid pressure reduction and slower pressure maintenance to achieve both ventilation improvement and airway stability
Data Source
AI summary
The device has a breathing gas source (21) for providing inspiratory positive airway pressure, and a sensor unit (22) for detecting pressure and/or flow values of breathing gas. A processor unit (23) processes values detected by the sensor unit, and a control unit (25) controls the source based on functions determined by a control panel (2) and an interface (8). The control unit triggers the source to pressure drop in the range of 30-300 hectopascal per second in a phase and triggers the source to another pressure drop in the range of smaller than 30 hectopascal per second in another phase. An independent claim is also included for a method for reducing inspiratory positive airway pressure to expiratory positive airway pressure or positive end-expiratory pressure.