Toward a Self-Inflating Bag Mechanical Ventilator, Maturation in Continuous Use, Safety, and Repeatability for...

Area of Science:

• Biomedical Engineering
• Respiratory Care

Background:

• Mechanical ventilators (MVs) using automated self-inflating bags (SIBs) were proposed during the COVID-19 pandemic.
• Previous SIB-based MV designs faced challenges with continuous use, variable repeatability, and gas exchange (PaCO2, FiO2).

Purpose of the Study:

• To demonstrate a novel automated SIB technology (Ehecatl-4T MV) for reliable, repeatable, and safe mechanical ventilation.
• To validate the device's performance in long-term use and preclinical settings.

Main Methods:

• The Ehecatl-4T (EHT) mechanical ventilator, based on SIB technology, was tested using a lung simulator for variable repeatability across different compliances and resistances.
• A long-term durability test was conducted to assess parameter stability.
• A preclinical study involved 12 pigs (87±5 kg) to evaluate ventilator-patient interaction and gas exchange.

Main Results:

• The EHT demonstrated acceptable relative errors in pressure and volume modes.
• The device operated continuously for over 32 days without compromising ventilatory variables.
• Preclinical studies showed partial pressure of carbon dioxide (PaCO2) and fraction of inspired oxygen (FiO2) levels close to reference values.

Conclusions:

• The Ehecatl-4T mechanical ventilator shows promise for continuous use with repeatable ventilatory variables, validated through bench testing.
• Clinical parameters in preclinical settings met industry safety standards, indicating safe ventilator-patient interaction.