A method is provided for reducing the risk of sustaining a traumatic brain injury caused by a traumatic event that includes identifying a subject at risk of sustaining a traumatic brain injury, and then precisely increasing the partial pressure of carbon-dioxide (CO.sub.2) in the blood of the subject (pCO.sub.2). This method can be applied to raise the CO.sub.2 and pCO.sub.2 to improve orthostatic hypotension in conditions such as dysautonomias (like Positional Orthostatic Tachycardic Syndrome POTS) and to facilitate the drive to breathe in conditions like Central Sleep Apnea (CSA) and Sudden Infant Death Syndrome (SIDS). The pCO.sub.2 of the person is increased by placing a breathing apparatus over the mouth of the person through which the person must breath, wherein the breathing apparatus includes an enlarged dead space volume in which expired CO.sub.2 collects to be inhaled or re-breathed by the person on the next inhalation.

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.

A device, system, and method for isolating a ventilator from one or more patients in which the delivery conditions of gas delivered to an isolation device from a ventilator may drive the delivery of breathing-gas delivered to one or more patients, the breathing-gas having the same or different delivery conditions. In one embodiment, an isolation device may have a housing and a movable partition. The movable partition may be joined to the housing, The movable partition may have a patient side on a first side of the partition and an actuating side on a second side of the partition. The isolation device may include an inlet pressure regulator on the actuating side and/or an exhaust pressure regulator on the patient side. These regulators may alter the delivery conditions (including, but not limited to, pressure and volume) of breathing-gas delivered to a patient.

Gas flow control valves comprising a valve housing including a cylindrical interior passage, and a housing opening extending from the interior passage through the housing. The gas flow control valve further comprises a cylindrical rotary valve element including a sidewall, and a rotary valve element opening extending through the sidewall. The valve element is rotatably received within the interior passage of the valve housing, such that the housing opening may be selectively aligned with the rotary valve element opening, and an area of overlap of the housing opening and the valve element opening may be varied by rotating the valve element within the interior passage of the valve housing.

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 nasal delivery device can include air-receiving section that has a first passageway therethrough to allow air to pass through the air-receiving section, a powder-reservoir receiving section sized to receive a powder reservoir, and a powder-delivery section that has a second passageway therethrough to allow aerosolized powder from the powder reservoir to pass through the powder-delivery section. The first passageway can have a first end and a second end, with the first end being further from the powder-reservoir receiving section and the second end being at or near the powder-reservoir receiving area. The second end of the air-receiving section can include a flattened region so that air exiting the air-receiving section has a generally flattened profile.

Gas mixture used for ventilation of passengers and crew in emergency situations. Depending on the density altitude, it has 75% CO.sub.2 at 15,000 ft flying altitude increasing to 175% CO.sub.2 at 30,000 ft flying altitude. The carbon dioxide improves the bioavailability of oxygen in the body. The gas mixture is produced by additive dosage of CO.sub.2 to either pure O.sub.2 or to a gas mixture having a fraction of N.sub.2 and a fraction of O.sub.2. The method for ensuring good ventilation in case of loss of cabin pressure, or generally in case of hyperventilation, involves making the gas mixture above available via respiration masks. The use of such a gas mixture also for ensuring good ventilation of people with limited mobility, if such ventilation is required. The prescribed amount of onboard oxygen for aircraft can thus be reduced and flight routes leading directly over high-altitude terrain may be taken.

An anesthetic circuit is provided for treating a patient. The anesthetic circuit includes a membrane having a plurality of hollow fibers. Also provided is a fluid separation apparatus connectable to an anesthetic circuit. In a further embodiment, a method is provided for anesthetic treatment of a patient.

Devices for delivery of dry powder formulations are also provided. Devices can be single-use devices. Formulations and methods of manufacture are provided for dry powder compositions suitable for intranasal administration. Also provided are methods of use for preventing or controlling emesis and other diseases and disorders and devices, compositions, and methods for nasal delivery of therapeutic formulations.

Examples of the invention include inhalation systems, breathing apparatuses, and methods for administering a solution by inhalation to a patient. Example breathing apparatuses described herein may be configured to minimize loss of the solution to the environment. Additionally or instead, example breathing apparatuses may be configured to recirculate exhaled solution to increase an amount of the solution available to a patient while minimizing exhausted solution. In some examples, breathing apparatuses may deliver nebulized platelet rich plasma (PRP).