The present disclosure relates to determining a corrected exhaled gas measurement during high flow respiratory therapy. Measuring exhaled gas concentration during high flow respiratory therapy is difficult and inaccurate due to a phenomenon known as flushing. The high flows delivered to the patient flush the dead space in the conducting airways, which causes a dilution effect that results in underestimated or overestimated exhaled gas measurement depending on the gas composition delivered by the high flow system. This can lead to incorrect clinical measurements and diagnoses. Various algorithms are disclosed herein to account for the dilution effect caused by flushing, allowing for the method of measuring gas concentrations to still be used accurately for clinical measurements.

A gases flow rate sensing system may be configured to operate in at least two different target temperature modes, based upon a measured temperature of the gases flow. In some embodiments, the gases flow sensing system may have a voltage divider containing a thermistor. The gases flow rate may be determined based upon a voltage output indicating an amount of power needed to maintain the thermistor at a target temperature as specified by the target temperature mode, and a measured temperature of the gases flow.

An oscillating positive respiratory pressure apparatus and a method of performing oscillating positive respiratory pressure therapy. The apparatus includes a housing having an interior chamber, a chamber inlet, a chamber outlet, an exhalation flow path defined between the inlet and the outlet, and a restrictor member rotatably mounted within the interior chamber. The restrictor member has an axis of rotation that is substantially perpendicular to the flow path at the inlet, and includes at least one blocking segment. Rotation of the restrictor member moves the at least one blocking segment between an open position and a closed position. Respiratory pressure at the chamber inlet oscillates between a minimum when the at least one blocking segment is in the open position and a maximum when the at least one blocking segment is in the closed position. By exhaling into the apparatus, oscillating positive expiratory pressure therapy is administered.

There is provided herein methods, apparatus and systems for evaluating carbon dioxide (CO.sub.2) concentration in a subject's breath, for example in subjects ventilated with High Frequency Ventilation (HFV), the method includes inserting to a trachea of a subject an endotrachial tube (ETT), sampling breath from an area in the trachea located in proximity to a distal end of the endotrachial tube (ETT) and evaluating one or more CO.sub.2 related parameters of the sampled breath.

The present invention provides an apparatus for nasally delivering a supraglottic jet ventilation and methods of treating breathing disorders by utilizing the apparatus for nasally delivering a supraglottic jet ventilation.

There is provided herein methods, apparatus and systems for evaluating carbon dioxide (CO.sub.2) concentration in a subject's breath, for example in subjects ventilated with High Frequency Ventilation (HFV), the method includes inserting to a trachea of a subject an endotrachial tube (ETT), sampling breath from an area in the trachea located in proximity to a distal end of the endotrachial tube (ETT) and evaluating one or more CO.sub.2 related parameters of the sampled breath.

Rhodamine dye is delivered to regions of a lung having heterogeneous alveolar flooding by alveolar liquid, thereby lowering the surface tension of the alveolar liquid so as to lessen ventilation injury directly and, by promoting equitable redistribution of the alveolar liquid among the alveoli of the lung, indirectly. The rhodamine dye is delivered with an albumin and/or an exogenous surfactant. Exemplary rhodamine dyes include sulforhodamine B and rhodamine WT.

A non-invasive ventilation system may include an interface. The interface may include at least one gas delivery jet nozzle adapted to be positioned in free space and aligned to directly deliver ventilation gas into an entrance of a nose. The at least one gas delivery jet nozzle may be connected to a pressurized gas supply. The ventilation gas may entrain ambient air to elevate lung pressure, elevate lung volume, decrease the work of breathing or increase airway pressure, and wherein the ventilation gas is delivered in synchrony with phases of breathing. A support for the at least one gas delivery jet nozzle may be provided. A breath sensor may be in close proximity to the entrance of the nose. A patient may spontaneous breathe ambient air through the nose without being impeded by the interface.

The present invention provides an apparatus for nasally delivering a supraglottic jet ventilation and methods of treating breathing disorders by utilizing the apparatus for nasally delivering a supraglottic jet ventilation.

Respiratory therapy apparatus has a short conduit (10) with a mouthpiece (13) at one end and open to atmosphere at its opposite end (11). One end of a cylinder (22), (110, 203) opens into the conduit (10) and contains a piston (21, 111, 205) slidable along the cylinder. The piston (21, 111, 205) carries a permanent magnet (24) that interacts with a magnetic field produced by electromagnetic coils (25, 26), 101-109 surrounding the cylinder. The coils are driven by a control unit (30) that receives inputs from pressure, flow and piston position sensors (40, 41) and (42) to cause the piston to oscillate in the cylinder and superimpose an oscillatory waveform on the normal tidal respiration along the conduit (10) at an amplitude sufficient to mobilize mucus in the patient's airway and produce a therapeutic effect.