A breathable gas inlet control device permits flow regulation at the inlet of a flow generator for a respiratory treatment apparatus such as a ventilator or continuous positive airway pressure device. The device may implement a variable inlet aperture size based on flow conditions. In one embodiment, an inlet flow seal opens or closes the inlet to a blower in accordance with changes in pressure within a seal activation chamber near the seal. The seal may be formed by a flexible membrane. A controller selectively changes the pressure of the seal activation chamber by controlling a set of one or more flow control valves to selectively stop forward flow, prevent back flow or lock open the seal to permit either back flow or forward flow. The controller may set the flow control valves as a function of detected respiratory conditions based on data from pressure and/or flow sensors.

The present invention relates to adjustable flow control valves, for example to an Adjustable Pressure Limiting (APL) valve. The adjustable valve (2) described comprises a valve body (4) comprising a valve seat (6), a valve member (10) movable relative to the valve seat (6), a first valve cap (20), a second valve cap (50) and a biasing element (30) to bias the valve member (10) away from the first valve cap (20). The first valve cap (20) is movable to increase the biasing force applied by the biasing element (30). The second valve cap (50) is engageable with the first valve cap (20) to prevent such movement of the first valve cap (20) beyond a selected position, but to allow movement of the first valve cap (20) in an opposite direction, way from said position.

A method for determining the functional residual capacity of a patient's lung, includes supplying a first inspiratory breathing gas having a first proportion of a metabolically inert gas, supplying a second inspiratory breathing gas having a second proportion of the metabolically inert gas, determining any arising volume difference, which represents a difference in volume between a volume of inspiratory and of expiratory metabolically inert gas for a determination period, determining the functional residual capacity taking into account the volume difference and a proportion difference between a first proportion quantity and a second proportion quantity, which represent the first proportion and the second proportion of the metabolically inert gas, respectively, and determining a base difference, which represents a difference between a tidal volume of inspiratory metabolically inert gas and of expiratory metabolically inert gas.

An exhalation device for a non-invasive ventilator, configured to reversibly convert between a passive ventilation configuration and an active ventilation configuration, comprising: (i) a housing with a first end and a second end, the housing defining a gas flow path extending between the first end and the second end; (ii) an exhalation port configured to passively release gas to the environment; (iii) an internal diaphragm positioned at an interface between the exhalation port and the housing, configured to allow release of gas exhalation; and (iv) an adapter comprising an adapter exhalation port and configured to reversibly engage the exhalation port to define a controlled exhalation flow path from the exhalation port to the adapter exhalation port, and comprising an internal air flow control configured to actively control the flow of exhalant through the controlled exhalation flow path.

A pressure regulating or pressure relief device comprises an inlet and an outlet chamber with an outlet. The inlet is in fluid communication with the outlet chamber. A valve seat is located between the inlet and the outlet. A valve member is biased to seal against the valve seat, and displaces from the valve seat by an inlet pressure at the inlet increasing above a pressure threshold to allow a flow of gases from the inlet to the outlet via the outlet chamber. The flow of gases through the outlet causes an outlet pressure in the outlet chamber to act on the valve member together with the inlet pressure to displace the valve member from the valve seat.

A gas valve (11) for ventilation which comprises a main body (12) having a first gas chamber (13), a second gas chamber (15) and at least an inlet duct (14) for supplying a gas to the first gas chamber (13). The gas valve (11) further comprises a proportional valve (24) for temporally sealing the first gas chamber (13) from the second gas chamber (15). The second gas chamber (15) comprises at least a second passage opening (22) for releasing the gas from the second gas chamber (15) and the second gas chamber (15) comprises a port (30) for connecting a pressure measurement apparatus for measuring the gas pressure in the second gas chamber (15). A circuit with a ventilation limb which comprises a gas valve (11) and a method for determining a releasing gas flow of a gas valve are also disclosed.

An expiratory valve (10) of a ventilation device (100), including a valve body (12) having a fluid inlet (14) and a fluid outlet (16) for breathing air of a patient formed therein the valve body (12) defining a fluid flow path between fluid inlet (14) and fluid outlet (16), with the cross-sectional area of the fluid flow path expanding in the direction towards the fluid outlet (16).

An exhalation valve for a ventilator apparatus for at least partial instrumental respiratory assistance of a patient, includes a valve housing with a flow passage which extends along a passage trajectory defining a local axial, radial and circumferential direction and along which respiratory air can flow through the valve housing. The valve housing has a housing-side valve sub-formation with a closed end surface which extends around the passage trajectory and towards which a mating surface of a valve body, movable relative to the valve housing and facing the end surface, can be pretensioned by the pretensioning force of a pretensioning device in such a way that the mating surface, when subjected to respiratory gas in an exhalation flow direction counter to the pretensioning force of the pretensioning device, is removable.

A patient ventilator system includes a patient delivery circuit having an inspiratory section that delivers an inspiratory gas flow to a patient and an expiratory section that receives expiratory gas flow from the patient, wherein a bidirectional blower motor drives the inspiratory gas flow in the inspiratory section and controls the expiratory gas flow in the expiratory section. A flow sensor measures gas flow rate between the bidirectional blower motor and the patient delivery circuit. A four quadrant controller is configured to control speed and direction of the bi-directional blower motor based on the measured flow rate so as to effectuate ventilation for the patient.

A variable throat jet venturi for delivering ventilation gas to a patient includes a jet nozzle, a deformable throat body arranged to receive ventilation gas output by the jet nozzle and defining a gas inlet and a gas outlet, and a housing containing the deformable throat body. The housing may define an entrainment opening which is open to ambient air and a pilot pressure port for pressurizing a plenum between an outer wall of the deformable throat body and an inner wall of the housing. A pilot pressure line may be fluidly coupled to the pilot pressure port. A controller may be programmed to energize the pilot pressure line to constrict the deformable throat body during an exhalation phase of positive end-expiratory pressure (PEEP) therapy.