Breath-Synchronized Flow-Targeted Ventilation for Lung Injury Mitigation
Solution Overview
Problem
Conventional mechanical ventilators using positive pressure ventilation can cause lung injury and discomfort, particularly in patients with acute lung injury or respiratory distress, and are challenging to liberate from ventilatory support, with low success rates for patients requiring prolonged mechanical ventilation.
Innovation Solution
A ventilator system that selectively delivers either breath-synchronized, flow-targeted ventilation (BSFTV) or closed-system positive-pressure ventilation (CSPPV) using a standard tracheal tube, allowing for synchronization of flow waveforms with the patient's breathing cycle to reduce airway pressure and work of breathing, and incorporating servo-controlled feedback for auto-titration of gas delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If positive pressure ventilation is used to deliver breaths to patients, then ventilation support can be provided to patients with respiratory failure, but lung injury and discomfort occur particularly in patients with acute lung injury
Solution Approach 1:
The patent inverts the conventional positive pressure ventilation approach by using negative pressure ventilation. Instead of pressurizing the airway to deliver breaths, the system creates subatmospheric pressure in the thoracic cavity to draw air into the lungs, thereby avoiding barotrauma and volutrauma associated with positive pressure ventilation
Solution Approach 2:
The patent replaces the mechanical positive pressure delivery system with a negative pressure generation system. The ventilator creates negative pressure swings that mimic natural breathing mechanics, substituting the harmful mechanical pressurization with a physiologically compatible negative pressure mechanism
2Reliability
If positive pressure ventilation is used to maintain airway pressure, then ventilation can be supported, but the patient's normal negative pressure inspiration is lost and work of breathing increases
Solution Approach 1:
The system inverts the pressure gradient approach by using negative pressure ventilation that preserves the patient's natural inspiratory drive. The ventilator generates negative pressure swings that augment rather than oppose the patient's spontaneous breathing efforts, maintaining normal respiratory mechanics and reducing work of breathing
Solution Approach 2:
The negative pressure ventilation system allows the patient's own respiratory drive to initiate and control breathing efforts. The ventilator provides supportive negative pressure swings that augment the patient's spontaneous inspiration rather than taking over breathing control, preserving the patient's self-service breathing mechanism
3Object-affected harmful factors
If flow-targeted ventilation synchronized to patient's breathing cycle is used, then airway pressure swings are mitigated and work of breathing is reduced, but the system complexity increases compared to conventional ventilators
Solution Approach 1:
The patent implements flow triggering and breath synchronization mechanisms that use feedback from the patient's spontaneous breathing efforts. The ventilator detects patient inspiration onset and synchronizes negative pressure delivery to augment each spontaneous breath, providing adaptive support that reduces airway pressure swings while managing system complexity through intelligent control
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 system mitigates airway pressure swings, reduces the work of breathing, and improves blood oxygenation, facilitating liberation from ventilatory support and reducing the need for tracheostomy or endotracheal tube replacement, while minimizing complications and discomfort.
Implementation Method 1
A flow sensor triggers a breath and the microprocessor synchronizes the delivery of the predetermined non-constant flow waveform to the detected breathing cycle of the patient
Implementation Method 2
A pressure transducer is positioned to measure airway pressure
Data Source
AI summary
A system selectively delivers either breath-synchronized, flow-targeted ventilation (BSFTV) or closed-system positive pressure ventilation (CSPPV) to augment respiration of a patient with a standard tracheal tube. A removable adaptor has a cap that can be removably attached to the proximal connector of the tracheal tube in BSFTV mode, and an inner cannula that extends within the tracheal tube to effectively divide it into two lumens. The adaptor includes a ventilator connector for removably engaging a ventilator hose to deliver air/oxygen through the adaptor and one lumen of the tracheal tube with a flow rate varying over each respiratory cycle in a predetermined waveform synchronized with the patient's respiratory cycle to augment the patient's spontaneous respiration. The adaptor also includes a port allowing the spontaneously-breathing patient to freely inhale and exhale in open exchange with the atmosphere through the other lumen.