A single respiratory cycle flow limitation detection method is disclosed. A patient gas delivery signal is received from one or more sensors in pneumatic communication with a ventilation source and a patient ventilation interface to a patient airway. The patient gas delivery signal is representative of a measure of therapeutic gas being delivered to the patient airway at a given time instant, and spans the single patient respiratory cycle. A second derivative of the patient gas delivery signal is generated and a total number of zero crossings therein are counted. These zero crossings are representative of an inflection change in the patient gas delivery signal. A flow limitation indication corresponding to the identified flow limitation is generated when there are at least two zero crossings in the second derivative of the patient gas delivery signal. An angle of deformation representing early, late, or mid-cycle obstruction onsets is generated.

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 valve module (20) for a ventilation system (100), includes a tube interface (21) for connection to a counter-tube interface (14) of an exhalation end (13) of a ventilation tube element (11) as well as a device interface (22) for connection to a counter-device interface (114) of an exhalation port (113) of a ventilator (110). The device interface has an exhalation valve section (24) providing an exhalation flow (93) of exhaled air (92) with an exhalation pressure (94). The exhaled air from the tube interface (21) flows through a module space (23). A ventilation tube device (10), the ventilator (110) as well as the ventilation system are provided with the valve module. Processes are provided for severing and establishing a connection between the device interface, the ventilation tube device and the counter-device interface of the exhalation port of the ventilator of the ventilation system.

A vent valve apparatus (10) for use with a system for supplying breathable gas pressurised above atmospheric pressure to a human or animal. The apparatus (10) includes a gas washout vent (15), a vent valve (18) adapted to progressively restrict the flow area of the washout vent (15), and a pressure sensitive vent valve control means (20,22,23). The control means is adapted to progressively cause the vent valve (18) to restrict the flow area of the gas washout vent (15) in response to increases in the pressure of the gas supply, thereby substantially regulating the volumetric flow of gas and/or CO.sub.2 gas through the washout vent (15) over a range of gas supply pressures.

A valve assembly, a ventilator, a process for operating a valve assembly and a computer program are provided. The valve assembly (10; 10a; 10b), for the ventilator (100), includes an inlet (12; 12a; 12b) configured for the inflow of a ventilation gas, an outlet (14; 14a; 14b) configured for the outflow of the ventilation gas and a volume flow control device (16; 16a; 16b) for the ventilation gas between the inlet and the outlet. The volume flow control device is configured to set the volume flow of the ventilation gas in a range between shut-off and a maximum volume flow and to provide an attenuation of a volume flow change during the opening, when the volume flow of the ventilation is increased, that differs from an attenuation occurring during the closing, when the volume flow of the ventilation gas is reduced.

A respiratory valve, such as a positive end expiratory pressure valve, permits pressure control for respiratory apparatus such as a ventilator or positive airway pressure device. The valve may include a flexible gas passage cover. The cover may be configured with a first side surface to operatively block and open an aperture of the gas passage at a valve seat to respectively prevent and permit gas flow through the aperture defined by the valve seat. The cover may include a second side surface opposite the first surface. The second surface may include at least one drop section forming a reduction in thickness of the cover between the first surface and the second surface. The first surface may include a coating to reduce friction of a membrane material of the first surface. The rim of the valve seat may comprise a variation in height relative the flexible cover.

A breathing assistance device includes a gas regulating valve. The gas regulating valve is operated by a linear actuator. The linear actuator may include a movable member that moves an obstruction member between an open position and a closed position. The linear actuator is isolated from a gas flow path through the valve.

A connection device, for mechanical ventilation and monitoring of spontaneous breathing of a patient (P), includes a fluid-guiding unit (9, 11, 15) and establishes a fluid connection between a medical arrangement (100) and a patient-side coupling unit (19). A volume flow sensor (90) measures an indicator of volume flow of fluid through the fluid-guiding unit. A volume flow sensor component (2) engages with an interior of the fluid-guiding unit. A homogenization unit (10) is nonrotatably inserted into the interior between the patient-side coupling unit and the component and includes two sieves and a connection element, which connects the sieves together. The homogenization unit homogenizes the flow of fluid through the fluid-guiding unit. An inner profile of the fluid-guiding unit and an outer profile of the homogenization unit together form a mechanical coding, which determines a defined rotation position of the homogenization unit in relation to the fluid-guiding unit.

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.

A ventilator for respiration gas supply, comprising a respiration gas source, a control unit, a memory, a pressure sensor and/or a flow sensor, an exchangeable respiration gas tube, at least one connection stub for the respiration gas tube, a patient interface and a valve. The control unit is set up to use signals from the pressure sensor and/or flow sensor to ascertain the patient's respiration phase and to ascertain the patient's current tidal volume during successive inhalations and exhalations and to compare a first set volume threshold for the tidal volume with the current tidal volume and to determine whether the latter is below the former and if so, to react by driving the respiration gas source to set a second pressure for the respiration gas for inhalation and driving the respiration gas source to set the CPAP pressure for the respiration gas for exhalation.