Gas mixing system for medical ventilator

A gas regulator for retrofitting a blower-based medical ventilator, the gas regulator comprising:

• a housing comprising a compressed gas inlet, an environmental gas inlet, and a mixed gas outlet;
• a plenum defined by the housing;
• a pressure sensor measuring a pressure of compressed gas inside the plenum;
• a mixing valve between the plenum and the mixed gas outlet;
• a pressure-regulating valve between the plenum and the compressed gas inlet;
• and
• a controller operatively coupled to the pressure-regulating valve.

A method of configuring a medical ventilator, comprising:

• providing a gas regulator comprising an oxygen inlet, an air inlet, a mixing valve, and a mixed gas outlet;
• fluidically coupling a source of compressed oxygen gas to the oxygen inlet of the gas regulator;
• fluidically coupling the mixed gas outlet of the gas regulator to an environmental gas inlet of the medical ventilator;
• operating the mixing valve to combine the compressed oxygen gas with air from the air inlet at a first ratio, to form a mixed gas;
• and
• providing the mixed gas to the environmental gas inlet of the medical ventilator, wherein the medical ventilator comprises a high-pressure oxygen inlet capable of being opened or closed.