A portable oxygen concentrator designed for medical use where the sieve beds, adsorbers, are designed to be replaced by a patient. The concentrator is designed so that the beds are at least partially exposed to the outside of the system and can be easily released by a simple user-friendly mechanism. Replacement beds may be installed easily by patients, and all gas seals will function properly after installation.

Described are nasal cannulas that improve the precision of the delivered dose for nitric oxide therapy by reducing the dilution of nitric oxide. The nasal cannulas may reduce the total volume and potential for retrograde flow during nitric oxide therapy through the design of the specific dimensions of the flow path and/or having check valves in the nitric oxide delivery line and/or having a flapper or umbrella valve dedicated to nitric oxide delivery. The nasal cannulas may also use materials that limit oxygen diffusion through the cannula walls. The nosepiece for these cannulas may be manufactured by a molding technique.

Sensing airflow and delivering therapeutic gas to a patient. At least some of the example embodiments are methods including: titrating a patient with therapeutic gas during a period of time when a flow state of breathing orifices is in a first state, the titrating results in a prescription titration volume; and then delivering the prescription titration volume of therapeutic gas to the patient when the flow state of the breathing orifices is in a second state different than the first state, the delivering only to the breathing orifices open to flow.

A ventilator includes an enclosure, a tubing configured to receive an input gas, and a flow outlet airline in fluid communication with the tubing. The flow outlet airline includes an airline outlet. The ventilator further includes a breath detection airline including an airline inlet. The airline inlet is separated from the airline outlet of the flow outline airline. The ventilator further includes a pressure sensor in direct fluid communication with the breath detection airline. The ventilator includes a controller in electronic communication with the pressure sensor and an internal oxygen concentrator in fluid communication with the tubing. The internal oxygen concentrator is entirely disposed inside the enclosure.

A ventilator includes a bidirectional breath detection airline and a flow outlet airline. The flow outlet airline includes an airline outlet. The ventilator further includes a breath detection airline including airline inlet. The airline inlet is separated from the airline outlet of the flow outline airline. The breath detection airline is configured to receive breathing gas from the user during exhalation by the user via the airline inlet. The ventilator further includes a pressure sensor in direct fluid communication with the breath detection airline. The pressure sensor is configured to measure breathing pressure from the user and generate sensor data indicative of breathing by the user. The ventilator further includes a controller in electronic communication with the pressure sensor. The controller is programmed to detect the breathing by the user based on the sensor data received from the pressure sensor.

Described are methods for safer nitric oxide delivery, as well as apparatuses for performing these methods. The methods may include detecting the presence or absence of a nasal cannula, and stopping the delivery of nitric oxide or providing an alert if the cannula is disconnected. The methods may also include purging the nasal cannula if it is reconnected after a disconnection or if it is replaced by a new cannula. Other methods pertain to automatic purging of the delivery conduit if the elapsed time between successive deliveries of therapeutic gas exceeds a predetermined period of time.

A non-invasive ventilation system may include at least one outer tube with a proximal lateral end of the outer tube adapted to extend to a side of a nose. The at least one outer tube may also include a throat section. At least one coupler may be located at a distal section of the outer tube for impinging at least one nostril and positioning the at least one outer tube relative to the at least one nostril. At least one jet nozzle may be positioned within the outer tube at the proximal lateral end and in fluid communication with a pressurized gas supply. At least one opening in the distal section may be adapted to be in fluid communication with the nostril. At least one aperture in the at least one outer tube may be in fluid communication with ambient air. The at least one aperture may be in proximity to the at least one jet nozzle.

A system for delivering oxygen comprises an oxygen source; a ventilator operatively connected to the oxygen source to receive a supply of oxygen therefrom; a valve having a) an open position in which the ventilator receives the supply of oxygen from the oxygen source and b) a closed position in which the ventilator is not in fluid communication with the oxygen source; a sensor configured to measure breath flow information for the patient; and a computer system to: determine a volume of gas delivered to the patient during a breath cycle of the patient and an inspiratory volume of gas delivered to the patient during an inspiration phase of the breath cycle by using the breath flow information; and provide input to the valve based on the determined volumes, the provided input causing a movement of the valve between the open and the closed positions.

Apparatus provide gas sensing operations such as for oxygen concentration sensing with an oxygen concentrator. In some versions, gas concentration sensing apparatus with pressure, temperature and/or mass flow sensors measure characteristics of a gas mixture in a vessel. A controller of the apparatus may estimate concentration of a constituent gas in the gas mixture as a function of the measured pressure, temperature and mass flow rate. In some versions, the sensing apparatus may measure a thermal conductivity of enriched gas, and, with a controller, estimate concentration of argon in the enriched gas from the thermal conductivity. The controller may estimate concentration of oxygen in the enriched gas from the concentration of argon. In some versions, an oxygen concentrator may have a mass flow sensor and a controller configured to trigger bolus delivery and/or measure oxygen concentration, and/or regulate bolus profile based on signals from the mass flow sensor.

A non-invasive ventilation system may include a nasal interface. The nasal interface may include a left outer tube with a distal end adapted to impinge a left nostril, at least one left opening in the left distal end in pneumatic communication with the left nostril, and a left proximal end of the left outer tube in fluid communication with ambient air. The left proximal end of the left outer tube may curve laterally away from a midline of a face. A right outer tube may be similarly provided. One or more left jet nozzles may direct ventilation gas into the left outer tube, and one or more right jet nozzles may direct ventilation gas into the right outer tube. The jet nozzles may be in fluid communication with the pressurized gas supply.