There is disclosed a simulation system for simulating a respiratory system. The simulation system includes a variable resistance device that provides a variable resistance to the airflow it receives to simulate a variation in resistance for the respiratory system during breathing and a variable elastance device that provides a variable elastance to the airflow it receives to simulate a variation in elastance for the respiratory system during breathing.

There is disclosed a simulation system for simulating a respiratory system. The simulation system includes a variable resistance device that provides a variable resistance to the airflow it receives to simulate a variation in resistance for the respiratory system during breathing and a variable elastance device that provides a variable elastance to the airflow it receives to simulate a variation in elastance for the respiratory system during breathing.

A breath analyte device includes a breath volume in fluid communication with a sampling volume. The device also includes a sampling sensor configured to generate a breath signal that varies in response to changes in gas pressure (e.g., sound waves) in the breath volume and one or more analyte sensors configured to generate one or more analyte signals that vary in response to a concentration of one or more target analytes present in the sampling volume. A control unit is configured to determine a time at which to measure the concentration of target analytes in the sampling volume based on the breath signal and measure the concentration of the target analytes based on the analyte signals at the determined time. The device may also include a pump configured to motivate gas from the breath volume into the sampling volume prior to measuring the concentration of the target analytes.

A multivariate spirometer and associated systems and methods are described. The spirometer has a housing defining a flow path and one or more sensors for detecting CO.sub.2 concentration values, temperature and/or flow rates of air in the flow path. The spirometer may be configured to generate time series data by sampling CO.sub.2 concentration values, temperature and/or flow rates at a predetermined frequency during inhalation and/or exhalation. Optionally, a processor is used to generate one or more output readings based on the CO.sub.2 concentration values, temperatures and/or flow rates.

A non-invasive method and system is provided for determining an internal component of respiratory effort of a subject in a respiratory study. Both a thoracic signal (T) and an abdomen signal (A) are obtained, which are indicators of a thoracic component and an abdominal component of the respiratory effort, respectively. A first parameter of a respiratory model is determined from the obtained thoracic signal (T) and the abdomen signal (A). The first parameter is an estimated parameter of the respiratory model that is not directly measured during the study. The internal component of the respiratory effort is determined based at least on the determined first parameter of the respiratory model. The first model parameter is determined based on the thorax signal (T) and the obtained abdomen signal (A) without an invasive measurement.

A non-invasive method and system is provided for determining an internal component of respiratory effort of a subject in a respiratory study. Both a thoracic signal (T) and an abdomen signal (A) are obtained, which are indicators of a thoracic component and an abdominal component of the respiratory effort, respectively. A first parameter of a respiratory model is determined from the obtained thoracic signal (T) and the abdomen signal (A). The first parameter is an estimated parameter of the respiratory model that is not directly measured during the study. The internal component of the respiratory effort is determined based at least on the determined first parameter of the respiratory model. The first model parameter is determined based on the thorax signal (T) and the obtained abdomen signal (A) without an invasive measurement.

A system includes an electrical tomography system and a volume estimation system. The volume estimation system is configured to reconstruct an initial impedance image based at least partially on received electrical tomography data of a domain, receive prior information associated with the domain, enhance the initial impedance image based at least partially on the received prior information to generate an enhanced impedance image, and based at least partially on the enhanced initial impedance image, generate a volumetric image of a region of interest of the enhanced impedance image, wherein the volumetric image represents a plurality of values indicating a volume of a fluid.

A system includes an electrical tomography system and a volume estimation system. The volume estimation system is configured to reconstruct an initial impedance image based at least partially on received electrical tomography data of a domain, receive prior information associated with the domain, enhance the initial impedance image based at least partially on the received prior information to generate an enhanced impedance image, and based at least partially on the enhanced initial impedance image, generate a volumetric image of a region of interest of the enhanced impedance image, wherein the volumetric image represents a plurality of values indicating a volume of a fluid.

The disclosure is directed to an apparatus and a method for improving manual ventilation and resuscitation by monitoring ventilation parameters and assisting resuscitation. The apparatus includes a gas flow sensor configured to measure a flow rate of exhaled gas of a subject. The apparatus is configured to receive an ideal body weight or a predicated body weight of the subject and calculate a first tidal volume range based on the ideal body weight or the predicated body weight of the subject. The apparatus is also configured to obtain an exhaled tidal volume of the subject based on the measured flow rate and determine whether the exhaled tidal volume is within the first tidal volume range. When it is determined that the exhaled tidal volume is not within the first tidal volume range, the apparatus is further configured to perform a first tidal volume warning.

An ear-worn device includes a speaker, an optical emitter, an optical detector, a processor, and a housing configured to be positioned within an ear of a subject, wherein the housing encloses the speaker, optical emitter, optical detector, and processor. The housing includes at least one window that exposes the optical emitter and optical detector to the ear of the subject, and the housing includes at least one aperture through which sound from the speaker can pass. Light transmissive material is located between the optical emitter and the at least one window and is configured to deliver light emitted from the optical emitter to an ear region of the subject at one or more predetermined locations. Light transmissive material is positioned between the optical detector and the at least one window and is configured to collect light external to the housing and deliver the collected light to the optical detector.