A filtration device including a fluid-impermeable housing having a gas inlet and outlet, and containing within the housing first filter media particles of an extended surface area substrate and containing at least one metal impregnant, and second filter media particles of an extended surface area zirconium hydroxide substrate and containing zinc (hydr)oxide. The first or second filter media particles also contain an amine-functional material. The device may be used in atmospheres containing various harmful gases, and may provide particularly useful improvements in breakthrough times for nitrogen dioxide, hydrogen sulfide, ammonia and formaldehyde compared to a device containing only the first filter media particles or only the second filter media particles.

A filtration device including a fluid-impermeable housing having a gas inlet and outlet, and containing within the housing first filter media particles of an extended surface area substrate and containing at least one metal impregnant, and second filter media particles of an extended surface area zirconium hydroxide substrate and containing zinc (hydr)oxide. The first or second filter media particles also contain an amine-functional material. The device may be used in atmospheres containing various harmful gases, and may provide particularly useful improvements in breakthrough times for nitrogen dioxide, hydrogen sulfide, ammonia and formaldehyde compared to a device containing only the first filter media particles or only the second filter media particles.

A method of detecting hypoxia. Detecting hypoxia includes detecting, in exhaled breath, at least one indicator for hypoxia. The at least one indicator is selected from the group consisting of pentanal, 2-pentanone, 2-hexanone, 2-heptanone, 2-cyclopenten-1-one, and 4-butyrolactone.

A gas distributor for a rebreather, the gas distributor being configured for connection with an inhale hose and with an exhale hose with a mouthpiece in between, wherein the gas distributor comprises a gas distributor housing, an inhale chamber at the gas distributor housing and comprising a first inhale port for connection with an inhale counterlung or with a scrubber, a second inhale port for connection with the inhale hose, and a gas supply valve for supplying gas on demand, an exhale chamber at the gas distributor housing and comprising a first exhale port for connection with an exhale counterlung or with a scrubber, a second exhale port for connection with the exhale hose, and an overpressure valve for opening in an event of overpressure, and a switch arranged at the gas distributor housing and configured for being switchable between an open circuit mode and a closed circuit mode.

A gas distributor for a rebreather, the gas distributor being configured for connection with an inhale hose and with an exhale hose with a mouthpiece in between, wherein the gas distributor comprises a gas distributor housing, an inhale chamber at the gas distributor housing and comprising a first inhale port for connection with an inhale counterlung or with a scrubber, a second inhale port for connection with the inhale hose, and a gas supply valve for supplying gas on demand, an exhale chamber at the gas distributor housing and comprising a first exhale port for connection with an exhale counterlung or with a scrubber, a second exhale port for connection with the exhale hose, and an overpressure valve for opening in an event of overpressure, and a switch arranged at the gas distributor housing and configured for being switchable between an open circuit mode and a closed circuit mode.

A wearable air filter system, including a mouth covering section, including a body, a fan disposed on at least a portion of a rear of the body to move air from a front of the body to a rear of the body, at least one purge valve angularly disposed on at least a portion of a base of the body to allow the air from the rear of the body to move through the at least one purge valve to the front of the body, such that the at least one purge valve prevents movement of the air from the front of the body through the at least one purge valve to the rear of the body, a first media unit disposed on at least a portion of a first side of the body, a second media unit disposed on at least a portion of a second side of the body opposite with respect to the first side of the body, a microphone disposed within at least a portion of the body to receive at least one external audio input therein, and an external speaker disposed on at least a portion of the body to emit at least one internal audio input therefrom, goggles removably connected to at least a portion of the body to prevent at least one of the air and at least one pathogen from moving therethrough, and a wearable control device connected to the mouth covering section to control operations of the mouth covering section and display a vitals reading thereon.

A wearable air filter system, including a mouth covering section, including a body, a fan disposed on at least a portion of a rear of the body to move air from a front of the body to a rear of the body, at least one purge valve angularly disposed on at least a portion of a base of the body to allow the air from the rear of the body to move through the at least one purge valve to the front of the body, such that the at least one purge valve prevents movement of the air from the front of the body through the at least one purge valve to the rear of the body, a first media unit disposed on at least a portion of a first side of the body, a second media unit disposed on at least a portion of a second side of the body opposite with respect to the first side of the body, a microphone disposed within at least a portion of the body to receive at least one external audio input therein, and an external speaker disposed on at least a portion of the body to emit at least one internal audio input therefrom, goggles removably connected to at least a portion of the body to prevent at least one of the air and at least one pathogen from moving therethrough, and a wearable control device connected to the mouth covering section to control operations of the mouth covering section and display a vitals reading thereon.

A mask assembly includes a mask configured to cover a mouth and nasal passage of the user, a valve coupled to the mask and configured to direct air out of the mask assembly, and a strap coupled to the mask. The mask assembly additionally includes a module removably coupled to the mask and configured to direct air into the mask assembly. The module includes a filter, an ultraviolet chamber, and a light source.

A mask assembly includes a mask configured to cover a mouth and nasal passage of the user, a valve coupled to the mask and configured to direct air out of the mask assembly, and a strap coupled to the mask. The mask assembly additionally includes a module removably coupled to the mask and configured to direct air into the mask assembly. The module includes a filter, an ultraviolet chamber, and a light source.

A system is described to protect a person from exposure to pathogens in breathing. A control device which can be an adjustable or removable filter, a valve to switch air sources, added substances interruption of the air stream is controlled by a determination made by a machine learning system with a machine learning model usually implemented as a neural network. The determination is made on the basis of training of the model which can be one or multiple stages with one stage in a large server not in real time and another stage in a field device which uses sensors and other information sources to acquire data to make a decision concerning the relative risk of various circumstances. Conditions detected include presence of other persons, level of activity of the protected person and many other factors concerning the surroundings, activity and history of the protected person.