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 system for providing respiratory support in cases of acute respiratory failure or severe trauma is described. The ventilator system comprises a ventilator and a tubing system. The system is characterized in that the ventilator comprises a continuous bleed valve configured to be open to air flow from the blower at all times when the blower is operating during both inspiration and expiration; thereby providing a minimal amount of pressure within a patient's lungs at the end of each exhalation—positive end expiratory pressure (PEEP). In an embodiment of the invention the system comprises a manifold block configured to hold the main operating elements of ventilator.

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 system for preventing cross-contamination in single-limb ventilators is described. In one embodiment, the system includes an airflow generator connected in-line to a humidifier, a first check valve and a patient interface by a gas flow circuit. A controller is electrically coupled to the airflow generator, and a cartridge is connected to the gas flow circuit between a first point downstream of the humidifier and a second point upstream of the patient interface. The cartridge includes a bacteria filter and the first check valve. A method for preventing cross-contamination in single-limb ventilators and a method for providing gaseous flow through a single-limb ventilator are also described.

A system for preventing cross-contamination in single-limb ventilators is described. In one embodiment, the system includes an airflow generator connected in-line to a humidifier, a first check valve and a patient interface by a gas flow circuit. A controller is electrically coupled to the airflow generator, and a cartridge is connected to the gas flow circuit between a first point downstream of the humidifier and a second point upstream of the patient interface. The cartridge includes a bacteria filter and the first check valve. A method for preventing cross-contamination in single-limb ventilators and a method for providing gaseous flow through a single-limb ventilator are also described.

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.

Gas flow control valves comprising a valve housing including a cylindrical interior passage, and a housing opening extending from the interior passage through the housing. The gas flow control valve further comprises a cylindrical rotary valve element including a sidewall, and a rotary valve element opening extending through the sidewall. The valve element is rotatably received within the interior passage of the valve housing, such that the housing opening may be selectively aligned with the rotary valve element opening, and an area of overlap of the housing opening and the valve element opening may be varied by rotating the valve element within the interior passage of the valve housing.

The present disclosure pertains to a system for controlling a leak flow rate during respiratory therapy. The system is configured to determine a leak flow rate necessary for CO.sub.2 expulsion for an individual subject and facilitate control of the leak flow rate during therapy such that the system exhausts substantially the entire exhaled volume of gas during an expiration of the subject. The system facilitates control of the leak flow rate during therapy via an adjustable leak valve. Determining the leak flow rate for the subject and facilitating control of the leak rate may minimize noise from air flow in the system, minimize the power draw needed by a pressure generator of the system, reduce a loss of medicine added to the respiratory therapy gas, and/or have other advantages, while still expelling the desired amount of CO.sub.2.

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.

The embodied invention is a new inspiration/expiration ventilator flow design, with a constant inspiration flow and intermittent-concurrent expiratory flow based on lung pressure setpoints. This mode is possible by using a new dual lumen tube inserted into a patient Trachea. Additionally, the control provides support for patient initiated breathing which is initiated by a lung pressure drop. This control provides continuous and gentle recruitment of lung alveoli.