Multiplex Ventilation: Solutions for Four Main Safety Problems

Area of Science:

• Biomedical Engineering
• Critical Care Medicine
• Respiratory Therapy

Background:

• The COVID-19 pandemic increased demand for mechanical ventilators, raising concerns about shortages.
• Sharing ventilators among multiple patients is proposed but poses risks due to differing lung mechanics.
• Previous simulations showed a 67% failure rate in ventilating multiple patients with a single machine.

Purpose of the Study:

• To evaluate novel devices developed for safe and effective multiplex ventilation.
• To address challenges in individual tidal volume (V_T) control and measurement.
• To assess individual PEEP (positive end-expiratory pressure) settings and measurement capabilities.

Main Methods:

• Utilized two lung simulators with a modified multiplex circuit and pressure control ventilation.
• Assessed individual devices: adjustable flow diverter valve, dual volume display, PEEP valve, and PEEP display.
• Evaluated the full circuit by ventilating 6 pairs of simulated patients with varying lung models.

Main Results:

• The adjustable flow diverter allowed independent V_T adjustment.
• The dual volume display showed an average error of -17%.
• PEEP valves individualized PEEP, though gauges had 17-41% error; however, the multiplex circuit equalized ventilation across different lung models.

Conclusions:

• Developed devices for individual V_T and PEEP control and display are effective.
• These innovations enhance the usability and patient safety of multiplex ventilation strategies.
• The study successfully reversed previous failure modes in simulated multiplex ventilation scenarios.