Portable oxygen concentrator elements are described including integrated sensor/accumulator assemblies, new muffler designs, and improved airflow and internal gas connectivity. The result of the elements is an extremely compact, light reliable portable oxygen concentrator that is easy to assemble and relatively inexpensive.

A method of identifying alveolar ventilation (V.sub.A) in a subject, the method comprising: (1) using a breathing circuit which, at exhalation, keeps exhaled gas separate from inhaled gas and at inhalation, when a first gas set (FGS) flow is less than the subject's minute ventilation (V.sub.E), results in a subject inhaling FGS first and then a second gas set (SGS), for the balance of inhalation; (2) setting the FGS flow at a rate greater that V.sub.E; (3) measuring an end tidal CO.sub.2 concentration at a steady state; (4) progressively lowering the FGS flow until a time equal to a recirculation time of CO.sub.2 in the subject; and (5) deriving V.sub.A as the rate of FGS flow at the intersection between an average PETCO.sub.2 in a steady state and a line fit to the PETCO.sub.2 values after the rise in PETCO.sub.2 values begins until the recirculation time.

A neck strap, a crown strap assembly and a headgear for a breathing mask. The neck strap for a headgear includes a one-piece main body adapted to engage a patient's neck, first and second lower connection portions adapted to connect to first and second lower mask connection straps, and first and second upper connection portions adapted to connect to respective first and second lateral crown straps.

A respiratory device for providing respiratory support to a patient includes an expandable bag and a rigid valve housing portion. The expandable bag includes an air intake valve, an adjustable predetermined tidal volume and a hinge configured to maintain the expandable bag in a predetermined tidal volume in an uncompressed configuration. The rigid valve housing portion in fluid communication with the expandable bag, the valve housing portion includes a peak inspiratory pressure (PIP) mechanism, an adjustable dial configured to adjust both the tidal volume of the expandable bag and a value of the PIP mechanism, a two-way valve configured to allow air to move from the expandable bag in a first direction through a first portion and directs air in an opposing direction through a second portion to create positive end-expiratory pressure (PEEP), and a PEEP controller comprising a PEEP dial configured to select a predetermined PEEP value provided by the two-way valve. The valve housing portion is capable of connecting to a patient breathing interface.

A mount configured for use within a respiratory system that provides a structure that facilitates coupling of a nebuliser downstream of a humidifier chamber and upstream of a conduit that delivers conditioned breathing gases to a patient or user. The mount can couple together a chamber, a nebulizer and a conduit.

Systems and methods may include a gas source, a gas delivery circuit, and a nasal interface allowing breathing ambient air through the nasal interface. A gas flow path through the nasal interface may have a distal gas flow path opening. A nozzle may be associated with a proximal end of the nasal interface a distance from the distal end gas flow path opening. At least a portion of an entrainment port may be between the nozzle and the distal end gas flow opening. The nozzle may deliver gas into the nasal interface to create a negative pressure area in the gas flow path at the entrainment port. The nasal interface and the nozzle may create a positive pressure area between the entrainment port and the distal end gas flow path opening. Gas from the gas delivery source and air entrained through the entrainment port may increase airway pressure or lung pressure or provide ventilatory support.

A system for reducing airway obstructions of a patient may include a ventilator, a control unit, a gas delivery circuit with a proximal end in fluid communication with the ventilator and a distal end in fluid communication with a nasal interface, and a nasal interface. The nasal interface may include at least one jet nozzle, and at least one spontaneous respiration sensor in communication with the control unit for detecting a respiration effort pattern and a need for supporting airway patency. The system may be open to ambient. The control unit may determine more than one gas output velocities. The more than one gas output velocities may be synchronized with different parts of a spontaneous breath effort cycle, and a gas output velocity may be determined by a need for supporting airway patency.

A gas delivery conduit adapted for fluidly connecting to a respiratory gases delivery system in a high flow therapy system, the gas delivery conduit includes a first connector adapted for connecting to the respiratory gases delivery system, a second connector adapted for connecting to a fitting of a patient interface, tubing fluidly connecting the first connector to the second connector where the first connector has a gas inlet adapted to receive the supplied respiratory gas, one of electrical contacts and temperature contacts integrated into the first connector. The gas delivery conduit further can include a sensing conduit integrated into the gas delivery conduit, where the first connector of the gas delivery conduit is adapted to allow the user to couple the first connector with the respiratory gases delivery system in a single motion.

A high flow therapy system for delivering heated and humidified respiratory gas to an airway of a patient includes a respiratory gas flow pathway for delivering the respiratory gas to the airway of the patient by way of a non-sealing respiratory interface; wherein flow rate of the respiratory gas is controlled by a microprocessor, a mixing area for mixing a first gas and a second gas in the respiratory gas flow pathway, a humidification area downstream of the mixing area and configured for humidifying respiratory gas in the respiratory gas flow pathway, and a heated delivery conduit for minimizing condensation of humidified respiratory gas.

A gas delivery conduit adapted for fluidly connecting to a respiratory gases delivery system in a high flow therapy system, the gas delivery conduit includes a first connector adapted for connecting to the respiratory gases delivery system, a second connector adapted for connecting to a fitting of a patient interface, tubing fluidly connecting the first connector to the second connector where the first connector has a gas inlet adapted to receive the supplied respiratory gas, one of electrical contacts and temperature contacts integrated into the first connector. The gas delivery conduit further can include a sensing conduit integrated into the gas delivery conduit, where the first connector of the gas delivery conduit is adapted to allow the user to couple the first connector with the respiratory gases delivery system in a single motion.