Physiologic closed-loop control for a ventilator that adapts to patient response time

A mechanical ventilator apparatus for customizing therapeutic delivery of gas to a patient, comprising:

• a gas delivery apparatus, having a patient interface, configured to deliver the gas to the patient;
• an oximetry sensor configured to generate signals representative of an oxygen concentration of the patient's blood;
• and
• a controller, comprising a processor and a memory, in communication with the gas delivery apparatus and the oximetry sensor, the controller configured to:
• receive the signals representative of the oxygen concentration of the patient's blood,
• determine the oxygen concentration of the patient's blood based at least in part on the received signals,
• provide a test change in an FIO2 setting of the gas being delivered to the patient,
• determine a patient response time based at least in part on the oxygen concentration of the patient's blood in response to the test change in the FIO2 setting, and
• adjust the FIO2 setting based at least in part on the determined patient response time and the oxygen concentration of the patient's blood.