Disclosed herein are methods, systems, and devices for controlling a gas mixture within a mechanical ventilator. According to one embodiment, a computer implemented method includes receiving first peripheral arterial oxygen saturation (SpO.sub.2) data from a pulse oximeter via a pulse oximeter interface, wherein the pulse oximeter is configured to monitor a patient receiving invasive ventilation; determining a first mode of operation for a ventilator mechanism, wherein the ventilator mechanism is configured to provide at least a portion of the invasive ventilation; determining first partial pressure of oxygen (PaO.sub.2) data stored in a first lookup table using the first SpO.sub.2 data, wherein the first lookup table is derived from a sigmoid shaped oxyhemoglobin dissociation curve; determining first fraction of inspired oxygen in air (FiO.sub.2) data for setting a mixture in a gas blender in the ventilator mechanism based on the first PaO.sub.2 data and a variable offset; and providing the FiO.sub.2 data to the ventilator mechanism.

Disclosed herein are methods, systems, and devices for controlling a gas mixture within a mechanical ventilator. According to one embodiment, a computer implemented method includes receiving first peripheral arterial oxygen saturation (SpO.sub.2) data from a pulse oximeter via a pulse oximeter interface, wherein the pulse oximeter is configured to monitor a patient receiving invasive ventilation; determining a first mode of operation for a ventilator mechanism, wherein the ventilator mechanism is configured to provide at least a portion of the invasive ventilation; determining first partial pressure of oxygen (PaO.sub.2) data stored in a first lookup table using the first SpO.sub.2 data, wherein the first lookup table is derived from a sigmoid shaped oxyhemoglobin dissociation curve; determining first fraction of inspired oxygen in air (FiO.sub.2) data for setting a mixture in a gas blender in the ventilator mechanism based on the first PaO.sub.2 data and a variable offset; and providing the FiO.sub.2 data to the ventilator mechanism.

Systems slow breathing with positive pressure therapy. In embodiments, a current interim breathing rate target is set, and periodically magnitude of a variable pressure waveform scaled to the current interim breathing rate target is increased if breathing rate is greater than the interim rate target to lengthen breath duration. The magnitude of the pressure increase may be a function of the difference between the interim rate target and the breathing rate. The interim rate target may be reduced in response to slowing breathing rate. The waveform cycles, inhalation to exhalation, when airflow decreases to a cycle threshold. Different interim rate targets have different cycle threshold functions that allow easier cycling as the interim rate targets decrease. Similarly, the waveform triggers, exhalation to inhalation, when airflow increases to a trigger threshold. Different interim rate targets have different trigger threshold functions that allow easier triggering as the interim rate targets decrease.

Systems slow breathing with positive pressure therapy. In embodiments, a current interim breathing rate target is set, and periodically magnitude of a variable pressure waveform scaled to the current interim breathing rate target is increased if breathing rate is greater than the interim rate target to lengthen breath duration. The magnitude of the pressure increase may be a function of the difference between the interim rate target and the breathing rate. The interim rate target may be reduced in response to slowing breathing rate. The waveform cycles, inhalation to exhalation, when airflow decreases to a cycle threshold. Different interim rate targets have different cycle threshold functions that allow easier cycling as the interim rate targets decrease. Similarly, the waveform triggers, exhalation to inhalation, when airflow increases to a trigger threshold. Different interim rate targets have different trigger threshold functions that allow easier triggering as the interim rate targets decrease.

A gas therapy system (1) has a flow line (3, 2), a coupler (6) to a gas source, and an aerosol generator (4) for aerosol delivery, and a patient interface such as a nasal interface (2). A controller (10) is configured to modulate gas flow and aerosol delivery in real time. The controller changes gas flow rate and dynamically reduces aerosol delivery during upper gas flow rates such as 60 LPM, and activates aerosol delivery during lower gas flow rates of for example 10 LPM. The control may also include sensors to detect breathing, so that there is a bias towards increased aerosol delivery during inhalation in addition to during lower level gas flow.

A method of determining a duration of safe apnoea. Information is obtained relating to a respiratory indicator, which can include information relating to a potential respiratory equilibrium, and a duration of safe apnoea is determined from the obtained information.

A method of determining a duration of safe apnoea. Information is obtained relating to a respiratory indicator, which can include information relating to a potential respiratory equilibrium, and a duration of safe apnoea is determined from the obtained information.

Systems and methods for hypoxia delivery are provided. An apparatus for providing intermittent normoxia and hypoxia intervals includes a breathing component, a normoxia fluid source, a hypoxia fluid source, a valve, and a control system. The valve is configured to disrupt flow from at least one of the normoxia fluid source and the hypoxia fluid source and the control system is configured to cause the at least one valve to switch between delivery of fluid from the normoxia fluid source and the hypoxia fluid source while maintaining positive pressure at the breathing component.

Systems and methods for hypoxia delivery are provided. An apparatus for providing intermittent normoxia and hypoxia intervals includes a breathing component, a normoxia fluid source, a hypoxia fluid source, a valve, and a control system. The valve is configured to disrupt flow from at least one of the normoxia fluid source and the hypoxia fluid source and the control system is configured to cause the at least one valve to switch between delivery of fluid from the normoxia fluid source and the hypoxia fluid source while maintaining positive pressure at the breathing component.