An anesthetic breathing apparatus and system, having a patient circle system for re-breathing exhaled gases by a patient a volume reflector, a fresh gas delivery line, and a gas sensor unit arranged to measure a gas stream upstream a fresh gas connection and downstream said reflector unit. The gas sensor unit provides a signal for detection of a reflector driving gas (RDG) crossing over the volume reflector during inspiration based on at least one property of the gas stream measured by the gas sensor unit. Appropriate action may be taken based on this measurement, for instance in disclosed methods.

The disclosed subject matter provides a device and a method for inducing and sustaining hypercapnia of a subject. The device can include a tube, a face mask for breathing of the subject, a gas collection reservoir for collecting an expired gas from the subject, a valve chamber, a sensor for detecting a carbon dioxide level from the expired gas from the subject, and a controller configured to control a partition of the valve chamber for changing a gas composition in the valve chamber based on the readings of the sensor. The valve chamber can include a first opening, a second opening, and a third opening, wherein the first opening can be configured to allow an external air flowing into the valve chamber, and the expired gas flowing out from the valve chamber, wherein the second opening, coupled to the face mask through the tube, can be configured to allow a gas passage between the subject and the valve chamber, wherein the third opening, coupled to the gas collection reservoir though the tube, can be configured to allow a gas passage between the valve chamber and the gas collection reservoir.

Provided herein are negative air pressure devices and uses thereof. In particular, provided herein are negative air pressure devices that modulate CO.sup.2 delivery for use in the treatment of sleep apnea.

Aspects discussed herein relate to remixing devices that can be used to modify a gas mix being inhaled by a user. The device can accurately adjust inspired CO.sub.2 and/or O.sub.2 levels independently to a desired level. Aspects described herein generally improve the quality, efficiency, and speed of devices to provide breathing gas mixes. Medical conditions can be diagnosed and a therapeutically effective gas mix can be provided as treatment for diagnosed medical conditions.

An apparatus and method for controlling the end tidal partial pressure of a gas X in a subject's lung, and to the use of such an apparatus and method for research, diagnostic and therapeutic purposes, wherein the method consists of: —obtaining input of a series of logistically attainable PetX values for a series of respective breaths: —determining an amount of gas X required to be inspired by the subject in an inspired gas to target the PetX for each of said respective breaths: and—controlling a gas delivery device to deliver the amount of gas in a volume of gas delivered to the subject in each of said respective breaths to target the respective PetX for that breath.

The present invention includes a device for hypoxia training including a breathable gas source; a mask in fluid communication with the breathable gas source; a mask-state detector that uses one or more criteria to determine if the mask is being worn by a subject, wherein the mask-state detector is capable of communicating an indication of a mask-off state or a mask-on state; a flowmeter in fluid communication with the mask and coupled to the mask-state detector; and a pressure regulator in fluid communication with the mask and with the breathable gas source, and coupled to the mask-state detector, wherein the pressure regulator sets a first pressure at the mask when the mask-state detector communicates an indication of a mask-off state or a second pressure at the mask when the mask-state detector communicates an indication of a mask-on state.

A virus attenuator includes: a housing defining an interior and having at least one intake port fluidly coupled to the interior and a gas ejection nozzle fluidly coupled to the interior, the gas ejection nozzle being configured to couple to a mask; and at least one heater disposed in the interior between the at least one intake port and the gas ejection nozzle such that at least some gas brought into the interior through the at least one gas intake port contacts the at least one heater. The at least one heater is configured to heat contacting gas to a virus attenuating temperature before the contacting gas exits the interior through the gas ejection nozzle.

A hypoxic training system is provided that dynamically adjusts the oxygen ratio in the gas provided to the user during a hypoxic training session based on the blood oxygen saturation (SPO.sup.2) level of the user. During a first training period, the hypoxic training system provides gas according to a first oxygen ratio. When it is determined that the SPO.sup.2 level of the user has reached a target SPO.sup.2 level, the hypoxic training system may provide a recovery period, during which gas according to a second oxygen ratio is provided to the user. When it is determined that the SPO.sup.2 level of the user has fallen more than a predetermined threshold below the target SPO.sup.2 level during the recovery period, the hypoxic training system may provide gas according to an increased first oxygen ratio during a subsequent training period.

Systems and methods are provided for detecting and sequestering waste anesthetic gases released by an anesthetic vaporizer. In one embodiment, a method for an anesthetic vaporizer installed in an anesthesia machine includes detecting an emission of waste anesthetic gases (WAGs) from the anesthetic vaporizer, and responsive to detecting the emission of WAGs, performing at least one of scavenging the WAGs and outputting an alert.

The invention is related to a portable rebreathing system for closed rebreathing. In order to minimize consumption of oxygen during rebreathing mode while safeguarding correct oxygen concentration, oxygen is added into the breathing passage using staged addition of oxygen via at least three individual oxygen supply valves 51, 52, 53. The two first oxygen supply valves are calibrated nozzles where one nozzle 51 is constantly delivering a predetermined amount of oxygen during normal breathing and the second nozzle 52 adds more oxygen at a second predetermined amount when the person to be treated is breathing heavily. The third valve is only opened manually and delivers a short burst of oxygen that fills the rebreathing system and its counter lung within seconds.