Some embodiments are directed to determining the composition of breath exhaled by a subject. For example, some embodiments are directed to determining a concentration of a gas species in breath exhaled by a human subject, based at least in part upon a measured concentration of the gas species in a chamber which is adapted to hold both breath exhaled by the human subject and ambient air for inhalation by the human subject.

An example device includes memory configured to store a measure of COPD severity of a patient and processing circuitry communicatively coupled to the memory. The processing circuitry is configured to receive an electromyogram (EMG) of the patient, receive one or more signals indicative of respiration rate of the patient, and receive one or more signals indicative of tidal volume of the patient. The processing circuitry is configured to determine, based on the respiration rate of the patient and the tidal volume of the patient, a minute ventilation of the patient. The processing circuitry is configured to determine, based on the minute ventilation of the patient and the EMG of the patient, the measure of COPD severity of the patient, and generate an indication for output that is based at least in part on the measure of COPD severity of the patient.

A fluid dynamic valve passively allows fluid flow out of a moving stream in one flow direction and not in the reverse. This allows the collection of fluid from a single direction of an AC fluid flow. The siphoned portion of the flow has a flow rate proportional to the mainstream flow. This device can collect exhaled breath or selective entrenchment during inhale. In one orientation, it can meter aerosolized particles into an inhale breath stream for pulmonary delivery, without complicated breath timing or drug loss due to drug adsorption to the back of the throat. Alternatively, a user can breathe through the device and a proportional amount, relative to the volumetric flow rate, of each exhale can flow into an auxiliary chamber for analysis. In addition, the device has a low respiratory burden and is comfortable to use.

Respiration system for non-invasive positive-pressure respiration, with a pressure source providing respiratory gas, with a control and evaluation unit connected to sensors detecting a leakage volume, spontaneous respiration frequency, tidal volume and the inspiration time. The control and evaluation unit I) checks the leakage volume and reduces the inspiratory pressure assistance proceeding to ii) or triggers an alarm and returns to I), ii) checks the frequency and triggers an alarm and returns to I) or reduces or increases the inspiratory pressure and returns to I) or proceeds to step iii), iii) checks the volume and reduces or increases the inspiratory pressure and returns to I) or leaves the pressure assistance unchanged proceeding to step iv), iv) adjusts the time period of the pressure assistance, depending on the inspiration time, the time period being left unchanged if the inspiration time lies in the predefined inspiration time interval, and returns to I).

This disclosure relates to a system configured to detect the presence of secretions in a subject's airway during respiratory therapy. The system can determine whether the subject requires airway clearance. A pressure generator generates a pressurized flow of breathable gas. Sensors generate output signals relating to one or more gas parameters of the pressurized flow of breathable gas. The system can determine a first parameter that is an indication of the volume of breathable gas within the airway of the subject and a time derivative of the first gas parameter to generate a plot of these parameters. The plot includes a perimeter and an area that can be used to determine whether to effectuate initiation of airway clearance based on a complete breathing cycle that includes at least one inhalation and exhalation.

This disclosure relates to a system configured to detect the presence of secretions in a subject's airway during respiratory therapy. The system can determine whether the subject requires airway clearance. A pressure generator generates a pressurized flow of breathable gas. Sensors generate output signals relating to one or more gas parameters of the pressurized flow of breathable gas. The system can determine a first parameter that is an indication of the volume of breathable gas within the airway of the subject and a time derivative of the first gas parameter to generate a plot of these parameters. The plot includes a perimeter and an area that can be used to determine whether to effectuate initiation of airway clearance based on a complete breathing cycle that includes at least one inhalation and exhalation.

Disclosed is a method for selectively capturing one or more portions of a patient's breath, comprising: detect one or more parameters regarding the patient's breath during a breathing routine; determine one or more data points from the detected one or more parameters wherein the one or more data points identifies one or more portions of the patient's breath to capture; and capture one or more portions of the patient's breath during the breathing routine.

Disclosed is a method for selectively capturing one or more portions of a patient's breath, comprising: detect one or more parameters regarding the patient's breath during a breathing routine; determine one or more data points from the detected one or more parameters wherein the one or more data points identifies one or more portions of the patient's breath to capture; and capture one or more portions of the patient's breath during the breathing routine.

The invention comprises a method of operating a breathing apparatus comprising measuring a baseline breath flow parameter being respiratory rate and/or tidal volume or a parameter derived therefrom, varying the flow rate provided by the breathing apparatus, measuring a current breath flow parameter being respiratory rate and/or tidal volume or a parameter derived therefrom, comparing the baseline and current breath flow parameters, and altering operation of the breathing apparatus based on the comparison. The invention also comprises a breathing apparatus that implements the above method.

The invention comprises a method of operating a breathing apparatus comprising measuring a baseline breath flow parameter being respiratory rate and/or tidal volume or a parameter derived therefrom, varying the flow rate provided by the breathing apparatus, measuring a current breath flow parameter being respiratory rate and/or tidal volume or a parameter derived therefrom, comparing the baseline and current breath flow parameters, and altering operation of the breathing apparatus based on the comparison. The invention also comprises a breathing apparatus that implements the above method.