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.

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.

Systems and methods for detecting worsening cardiac conditions such as worsening heart failure events are described. A system may include sensor circuits to sense physiological signals and signal processors to generate from the physiological signals first and second signal metrics. The system may include a risk stratifier circuit to produce a cardiac risk indication. The system may use at least the first signal metric to generate a primary detection indication, and use at least the second signal metric and the risk indication to generate a secondary detection indication. The risk indication may be used to modulate the second signal metric. A detector circuit may detect the worsening cardiac event using the primary and secondary detection indications.

In a method and breathing apparatus for prediction of fluid responsiveness of a subject connected to a breathing apparatus, at least one parameter is monitored that is indicative of a degree of carbon dioxide elimination of the subject, and a positive end expiratory pressure PEEP regulator of the breathing apparatus is operated to apply a PEEP maneuver in which a PEEP applied to the subject is changed from a first PEEP level to a second PEEP level. A processor predicts the fluid responsiveness of the subject based on a change in the monitored parameter, following the change in PEEP.

A monitoring apparatus includes a wearable electronic device having an audio port and a headset having at least one earbud, at least one physiological and/or environmental sensor, and circuitry that processes signals produced by the at least one physiological and/or environmental sensor and transmits the processed signals to the electronic device via the audio port. The headset may include a microphone in audio communication with the electronic device via the audio port, and the circuitry modulates audio signals produced by the microphone and signals produced by the at least one physiological and/or environmental sensor for transmission to the electronic device via the audio port. The circuitry may power the at least one physiological and/or environmental sensor via power supplied by the electronic device through the audio port and may include a processor that coordinates collection, modulation, and/or transmission of signals produced by the at least one physiological and/or environmental sensor.

The present invention provides an apparatus for the measurement and monitoring of the breathing volume of a subject. In certain embodiments, the invention further provides a method of using the apparatus to diagnose a subject as suffering from a respiratory disorder. In other embodiments, the apparatus and method can be used to monitor the breathing volume of a subject, while compensating for random body movement of the subject during the monitoring period.

The present invention provides an apparatus for the measurement and monitoring of the breathing volume of a subject. In certain embodiments, the invention further provides a method of using the apparatus to diagnose a subject as suffering from a respiratory disorder. In other embodiments, the apparatus and method can be used to monitor the breathing volume of a subject, while compensating for random body movement of the subject during the monitoring period.

Systems and methods for detecting a worsening of patient's heart failure condition based, at least in part, on an increasing trend in a representative rapid shallow breathing index (RSBI) value over multiple days. The RSBI value may be a minimum RSBI, and more particularly may be a minimum RSBI value determined for an afternoon portion of each of the multiple days. The minimum RSBI value measured during an afternoon portion of the day may be more sensitive to changes in a patient's respiration, particularly when a patient is expected to be more active, and thus, may more readily exhibit an increasing trend when patient's heart failure is in decline.

Systems and methods for detecting a worsening of patient's heart failure condition based, at least in part, on an increasing trend in a representative rapid shallow breathing index (RSBI) value over multiple days. The RSBI value may be a minimum RSBI, and more particularly may be a minimum RSBI value determined for an afternoon portion of each of the multiple days. The minimum RSBI value measured during an afternoon portion of the day may be more sensitive to changes in a patient's respiration, particularly when a patient is expected to be more active, and thus, may more readily exhibit an increasing trend when patient's heart failure is in decline.

Devices and methods for monitoring physiologic parameters are described herein which may utilize a non-invasive respiratory monitor to detect minor variations in expiratory airflow pressure known as cardiogenic oscillations which are generated by changes in the pulmonary blood volume that correspond with the cardiac cycle. These cardiogenic oscillations are a direct indicator of cardiac function and may be used to correlate various physiologic parameters such as stroke volume, pulmonary artery pressure, etc.