A pressurized flow of breathable gas is delivered to the airway of a subject through a gas circuit (16) as part of a therapy regime. Leakage of gas from within the circuit to atmosphere to prevent re-breathing of gas is dynamically adjusted to stabalize the total amount of leakage.

A positive airway pressure device is disclosed herein. The positive airway pressure device includes a blower, a buffer chamber, a gas manifold, a first sensor, a second sensor, and a controller. The buffer chamber is downstream of the blower. The buffer chamber configured to receive gas generated by the blower and output the gas to a patient. The gas manifold is fluidly coupling the blower to the buffer chamber. The first sensor is at least partially disposed in the gas manifold. The first sensor is configured to measure a first pressure in the gas manifold. The second sensor is at least partially disposed in the buffer chamber. The second sensor is configured to measure a second sensor in the buffer chamber.

Described is an apparatus for oxygenation and/or CO2 clearance of a patient, comprising: a flow source or a connection for a flow source for providing a gas flow, a gas flow modulator, a controller to control the gas flow, wherein the controller is operable to: receive input relating to heart activity and/or trachea gas flow of the patient, and control the gas flow modulator to provide a varying gas flow with one or more oscillating components with a frequency or frequencies based on the heart activity and/or trachea flow of the patient.

A respiratory flow therapy apparatus including a sensor module can measure a flow rate of gases or gases concentration provided to a patient. The sensor module can be located after a blower and/or mixer. The sensor module can include at least an ultrasonic transmitter, a receiver, a temperature sensor, a pressure sensor, a humidity sensor and/or a flow rate sensor. The receivers can be immersed in the gases flow path. The receivers can cancel delays in the transmitters and improve accuracy of measurements of characteristics of the gases flow. The receivers can allow for detection of a fault condition in a blower motor of the apparatus.

Methods and systems are provided for delivering anesthetic agent to a patient. In one embodiment, an anesthetic vaporizer includes a vaporizing chamber configured to hold a liquid anesthetic agent; a grid disposed within the vaporizing chamber; and a heating element positioned relative to the vaporizing chamber and configured to increase the temperature of the grid.

Apparatus and methods for delivering humidified breathing gas to a patient are provided. The apparatus includes a humidification system configured to deliver humidified breathing gas to a patient. The humidification system includes a vapor transfer unit and a base unit. The vapor transfer unit includes a liquid passage, a breathing gas passage, and a vapor transfer device positioned to transfer vapor to the breathing gas passage from the liquid passage. The base unit includes a base unit that releasably engages the vapor transfer unit to enable reuse of the base unit and selective disposal of the vapor transfer unit. The liquid passage is not coupled to the base unit for liquid flow therebetween when the vapor transfer unit is received by the base unit.

A high flow therapy system for delivering heated and humidified respiratory gas to an airway of a patient, the system including 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 pressurized respiratory gas is controlled by a microprocessor.

An improved patient interface assembly and pressure support system integrate a pressure sensor and a valve into the patient interface assembly and employs closed loop control between the sensor and the valve in order to limit delay between the time at which a condition indicative of abnormal breathing or flow load during normal breathing is experienced by a patient and the time at which altered pressure support is received by the patient.

Provided is an oxygen concentration device which, as an oxygen concentration device having a reduced difference in flow rates of gas which flows through a pressure equalization valve of a pressure equalization path during a purge step and a pressure equalization step, is provided at at least one end side of the pressure equalization valve with a pressure control member having a difference in pressure loss due to the direction of gas flow so that pressure loss of the gas which flows through the pressure equalization path in one direction becomes nearly equal to that of the gas which flows therethrough in the opposite direction.

A fluid delivery system provides fluid, such as supplement oxygen, to a patient in response to inhalation. The fluid delivery system includes a valve assembly that is triggered by sensing onset of inspiration by measuring a change in temperature of air flow in a nasal or oral cannula, mask or helmet.