A capnography system (100, 400), comprising: a controller (110, 410) configured to obtain a sample gas flow from a physical interface (107) for a patient (101); determine a change in a characteristic of the sample gas flow during a sampling time interval; determine whether the change in the characteristic of the sample gas flow during the sampling time interval is equal to or greater than a corresponding threshold value; determine that supplemental oxygen is provided when it is determined that the change in the characteristic of the sample gas flow is equal to or greater than the threshold value; and determine that supplemental oxygen is not provided when it is determined that the change in the characteristic of the sample gas flow is less than the threshold value.

Systems and methods for generating and delivering nitric oxide are provided. In one aspect, a nitric oxide generator includes an inlet arranged to receive a gas including nitrogen and oxygen, an outlet, a pair of electrodes arranged downstream of the inlet and configured to generate nitric oxide from the gas, a pressure regulator configured to selectively adjust a pressure of the gas surrounding the electrodes, an accumulator in communication with the pressure regulator, a nitric oxide sensor arranged to measure a concentration of nitric oxide at the outlet, and a controller in communication with the pair of electrodes, the pressure regulator, and the nitric oxide sensor. The controller is configured to selectively instruct the pressure regulator to adjust the pressure of the gas surrounding the electrodes in response to the concentration of nitric oxide measured at the outlet by the nitric oxide sensor.

A breath detection apparatus for monitoring individual breaths of a patient. The apparatus includes a sensing assembly comprising a humidity sensor. The sensing assembly adapted to be connected to an oxygenation device wherein respiratory gases of a patient are directed over the sensing assembly and the humidity sensor is adapted to monitor differences in humidity during a breath of the patient. The humidity sensor generates an electrical signal representing a humidity level in response to measuring the humidity during the breath. The apparatus also includes a processor in electrical communication with the sensing assembly to receive electrical signals generated by the humidity sensor and determine a state of the relative humidity during the breath, and a visual display element controlled by the processor and adapted to display a predetermined visual alert in response to the state of the relative humidity during the breath.

Methods and apparatus may implement controlled generation of oxygen enriched air in an oxygen concentrator while implementing control that reduces pneumatic imbalance between the concentrator's canisters, such as dynamic pressure imbalance or other pneumatic characteristic. One or more controllers may regulate operation of a compressor that feeds a pressurised air stream to the concentrator's canisters. This may regulate speed of the compressor to a speed set point for generating the pressurised stream. The regulating may involve generating a compressor control signal having a characteristic parameter such as a power parameter. The controller(s) may operate valve(s) in a cyclic pattern so as to produce oxygen enriched air in an accumulator. A cycle of the cyclic pattern may include a plurality of phases, where each of the plurality of phases has a duration. The controller(s) may then generate a dynamic adjustment to the duration(s) based on an evaluation of the characteristic parameter.

There is provided herein, a bite block (100) comprising an insertion channel (134) and an airway channel (132) wherein the airway channel is adapted to receive exhaled breath and wherein the first insert channel is adapted to pass a medical instrument. There is provided herein, a bite block comprising an oral insert channel, wherein a portion of said channel opens into a cavity (142) adapted to slidably receive an oral prong (270) the oral insert channel is adapted to receive exhaled breath.

A gas delivery conduit adapted for fluidly connecting to a respiratory gases delivery system in a high flow therapy system. In one embodiment, a nasal cannula includes a base portion defining a first therapeutic gas passageway, a nozzle disposed adjacent the base portion and defining a second therapeutic gas passageway, the first passageway being in gaseous communication with the second passageway and a conduit configured to facilitate sensing that has an inlet side that is independent of and axially spaced apart from an outlet side of the nozzle. The conduit inlet side can extend beyond the nozzle outlet side of the nasal cannula. Additionally, the nasal cannula has a feature adapted to prevent one of the conduit and the nozzle from creating a seal with a user's rare and a feature adapted to prevent one of the conduit and the nozzle from creating a seal with a user's nare.

A processor obtains input of a logistically attainable end tidal partial pressure of gas X (PetX[i].sup.T) for one or more respective breaths [i] and input of a prospective computation of an amount of gas X required to be inspired by the subject in an inspired gas to target the PetX[i].sup.T for a respective breath [i] using inputs required to utilize a mass balance relationship, wherein one or more values required to control the amount of gas X in a volume of gas delivered to the subject is output from an expression of the mass balance relationship. The mass balance relationship is expressed in a form which takes into account (prospectively), for a respective breath [i], the amount of gas X in the capillaries surrounding the alveoli and the amount of gas X in the alveoli, optionally based on a model of the lung which accounts for those sub-volumes of gas in the lung which substantially affect the alveolar gas X concentration affecting mass transfer.

Devices and systems for monitoring weaning of a subject from a respiratory ventilator including a processing logic configured to characterize distinct patterns in a series of CO.sub.2 waveforms, the distinct patterns indicative of the effectiveness of a weaning process; and to provide an indication relating to the effectiveness of the weaning process.

Systems and methods for collecting breathing gas properties via a medical ventilatory filter and wirelessly transmitting the data to another device. For example, the filter includes a first housing enclosing filtration media for filtering breathing gases flowing through the filter, the first housing defining a first port and a second port exposed to the breathing gases; and a sensor assembly. The sensor assembly includes a first sensor coupled to the first port, the first sensor configured to capture measurement data for a first gas property of breathing gases flowing through the filter; a second sensor coupled to the second port, the second sensor configured to capture measurement data for a first gas property of the breathing gases flowing through the filter; and a second housing. The second housing includes a processor and communication circuitry operative to wirelessly communicate the sensor data to a computing device located remotely from the filter.

A computer-implemented method is described. The method includes receiving an indication and determining a subject's oxygen consumption based on the indication. The indication refers to an oxygen fraction in a sample of inhalation gas delivered by a ventilator for inhalation by a subject. The indication further refers to an oxygen fraction in a sample of exhalation gas exhaled by the subject. The indication further refers a measurement of a flow rate of the exhalation gas.