Abstract: The invention provides new systems/methods for providing oxygen to chronically ill patients, such as COPD patients, through a more efficient portable oxygen concentrator (“POC”) that at least sometimes delivers an enriched airflow having a significantly lower overall oxygen concentration than that administered by typical POCs. In aspects, the methods/systems of the present invention are configured to automatically switch from pulse delivery to continuous delivery, from continuous delivery to pulse delivery, or any combination thereof, at least once per day, when certain conditions occur. Methods/system can comprise the ability to switch between mode(s) comprising delivery of a moderately enriched oxygen airflow (MEOA) and mode(s) comprising delivery of intensively enriched oxygen airflow, highly enriched oxygen airflow, or both, and back again, based on one or more parameters.

Abstract: An air breathing device includes a casing and an air passage cavity encompassed by the casing. The device includes a set of air intake ports and air discharge ports that connect the air passage cavity to the outside of the casing. The device includes a set of dampers that allow the air to flow into the air passage cavity during inhalation through the air intake ports. The device includes a set of dampers that allow the air to exit the air passage cavity during exhalation through the air discharge ports. The device includes a retractable display screen to display content to the wearer. The device includes a fixed display screen to display images of the mouth of the wearer captured by a camera lens or simulated based on captured voice of the wearer. The device includes UV lights, filters, network connections, camera lenses, speakers, microphones, ear plugs, and heating coils.

Abstract: There is provided a method of controlling a powered air purifying respirator blower system to deliver a substantially uniform volumetric airflow to a user, the system comprising a fan powered by a battery in communication with a variable speed electric motor, the variable speed electric motor is controlled by an electronic control unit for delivering a forced flow of air through at least one filter to a user, comprising the steps of: (a) determining an estimated system run time by summing a battery run time remaining and a system run time; and (b) altering a speed of the variable speed electric motor when the estimated system run time is equal to or less than a desired system run time.

Abstract: A personal protection and ventilation system is provided. The system includes a gown having front and rear panels, a hood, and visor; a fan; an air tube; and a helmet. The fan is positioned between the wearer and a body-facing surface of the rear panel. The front panel and at least a portion of the hood are formed from a first material including a first spunbond layer, a spunbond-meltblown-spunbond laminate, and a liquid impervious elastic film disposed therebetween. The first material has an air volumetric flow rate of less than about 1 standard cubic feet per minute (scfm). The rear panel is formed from a second material including a nonwoven laminate having an air volumetric flow rate of about 20 scfm to about 80 scfm. Therefore, the fan is able to intake a sufficient amount of air from the environment through the rear panel to provide cooling/ventilation to the hood.

Abstract: A personal protection and ventilation system is provided. The system includes a gown having front and rear panels, a hood, and visor; a fan; an air tube; and a helmet. The fan is positioned between the wearer and a body-facing surface of the rear panel. The front panel and at least a portion of the hood are formed from a first material including a first spunbond layer, a spunbond-meltblown-spunbond laminate, and a liquid impervious elastic film disposed therebetween. The first material has an air volumetric flow rate of less than about 1 standard cubic feet per minute (scfm). The rear panel is formed from a second material including a nonwoven laminate having an air volumetric flow rate of about 20 scfm to about 80 scfm. Therefore, the fan is able to intake a sufficient amount of air from the environment through the rear panel to provide cooling/ventilation to the hood.

Abstract: A patient interface structure for delivery of respiratory therapy to a patient includes a cushion assembly that has an elastomeric piece with a mouth seal portion configured to seal around the patient's mouth and a nasal seal portion configured to seal against at least an underside of the patient's nose. The cushion assembly also has a cushion clip attached to the elastomeric piece and forms at least part of a plenum chamber with the elastomeric piece. The cushion clip is more rigid than the elastomeric piece. A front plate that is more rigid than the elastomeric piece and has a plurality of headgear attachment points is attachable to the cushion clip by way of a snap fit connection. A gas passage extends along a surface of the front plate and includes an inlet opening configured to connect to an air delivery tube or a connector for an air delivery tube.

Abstract: An object of the present invention is to provide a breathing apparatus, wherein current for keeping internal pressure of the face piece at a predetermined positive target value at the time of inhale is not applied to the motor fan in a large amount at the start of current application to the motor fan, and the internal pressure of the face piece is prevented from becoming far below the predetermined positive target value immediately after start of current application to the motor fan so as to keep the internal pressure of the face piece at the predetermined positive target value at the time of inhale.

Abstract: Embodiments relate generally to methods and systems for refreshing filter media within a respirator and indicating end of service life for the filter media. A respirator may include a rollable filter media configured to be refreshed by rolling the filter media onto a roller. A rolling mechanism may rotate the roller, allowing for a fresh section of filter media to be placed in the air path of the respirator. The rolling mechanism may be controlled automatically by a motor and/or manually.

Abstract: A barrier system, device, and method protects medical professionals and patients from exposure to contaminants and bodily fluids is provided. The system includes a head unit shaped to be worn over the head of the wearer; a hood positioned over the head unit; one or more sensors configured to produce one or more sensor-output signals; and a controller connected to the one or more sensors and configured to produce one or more controller-output signals based on the one or more sensor-output signals. Further, a device inside a barrier system is controlled by (a) sensing one or more characteristics; (b) producing one or more sensor signals based on the sensed one or more characteristics; (c) converting and/or processing the one or more sensor signals to produce one or more controller-output signals; and (d) controlling the device based on the one or more controller-output signals.

Abstract: This invention is a pathogen-filtering face mask with a transparent portion over a wearer's mouth which enables other people to see the wearer's facial expressions and with active filtration of air entering and exiting the mask, with a relatively unobtrusive design. This mask can include a transparent portion which covers at least part of a person's mouth, a first-side air filter and air impellor, a second-side air filter and air impellor, and a central air filter between the first-side air filter and the second-side air filter.

Abstract: The invention relates to a modular, portable, air purifier device capable of supplying filtered or otherwise conditioned airflow to an individual. More specifically, the present invention provides an air purification system that allows for the remote detection and analysis of local ambient air quality and transmit that information to wirelessly connected devices.

Abstract: An improved underwater breathing and motion system is disclosed. The improved underwater breathing and motion system may include an air inlet for receiving air from a surface of the water, a system for assisting a diver with motion, and an insulated casing for housing various elements which include an air filtration unit for filtering the air received from the surface, a compressor for compressing the filtered air, a storage unit for storing the compressed air, and a regulator for regulating a pressure of the compressed air when the compressed air is transmitted to a mouthpiece for breathing by a diver.

Abstract: The present invention relates to a sleep-inducing system using carbon dioxide. The sleep-inducing system includes a mixed gas generation unit which generates a mixed gas of which a carbon dioxide concentration is within a preset range by mixing provided carbon dioxide and air, an emission unit which sprays the mixed gas from a position spaced apart from a user's face, a concentration sensing sensor which measures the carbon dioxide concentration of the sprayed mixed gas, and a control unit which controls the carbon dioxide concentration of the mixed gas generated by the mixed gas generation unit to be within the preset range on the basis of the measured carbon dioxide concentration.

Abstract: A hardhat with a protected overhead cooling fan comprises: a main hardhat body component having an upper aperture through which air is drawn and pulled down into a battery powered cooling fan; a fan cover component spaced at least about ¼ inch from and permanently adhered to the main hardhat body with a plurality of linear ridges; a battery pack for the cooling fan; and a plurality of connecting wires. A method of use is also disclosed.

Abstract: A personal protective device (PPE) including a face cover assembly and a bodysuit configured to be worn by a human user. The device protects users against airborne aerosol particles containing viruses or other infectious agents while enabling improved flexibility relative to prior art designs. The device includes a helmet-like” rotating face cover assembly that fits over the user's head and attaches to a collar on the biohazard bodysuit. This rotating face cover assembly has a plurality of different mask sides, each with differing geometries or other properties. The device enables a user to can rotate the cover and select a given mask side that best meets that user's needs. The different mask sides can accommodate different facial geometries, eyewear types, and use cases.

Abstract: A low pressure drop device for personal protection against toxic industrial chemicals and chemical warfare agents has a flexible polymer hood impermeable to toxic challenge molecules, a neck seal for sealing the hood about the neck, a half mask for connection to a canister and a low pressure drop canister for chemical protection. The canister contains carbon monoliths of 5- 40 mm diameter, length 1-3 cm, open area 30-60%, surface area ?700 m2/g optionally activated to >30 wt % weight loss and optionally impregnated with metallic additives and/or triethylene diamine. The monoliths have square channels of size 100-2000 ?m and wall thickness 100-2000 ?m. It also contains a resiliently flexible closed cell foam with holes slightly smaller than the monoliths so that flow through the canister is through the monoliths.

Abstract: A multi-purpose protection mask for protecting the human face and head against viruses, bacteria, dust or environmental harsh impacts is presented. It has four elements. A face shield transparent sheet covers comfortably the user's face providing adequate space for freely breathing and wearing glasses. A removable and replaceable filter mask element which is a multi-layer filter piece of a proper material affixed over an opening window in the face shield. A ventilator for draining and filtering the exhalation air and humidity before dumping into the atmosphere and it consists of exhaust fans, suction tubes, suction vents, and exit filters. The ventilator prevents condensation of fogging on the face shield and glasses. Another element is a head cover mask made of a fabric material affixed to the face shield element. Fastener strips means are provided for keeping the face shield comfortable and stable on the wearer's face.

Abstract: A personal protection system including a helmet worn on the head of a user and a hood removably coupled to the helmet. The helmet may comprise a ventilation assembly, a chin bar and a control circuit. The chin bar may comprise a mounting device and a hall effect sensor mounted adjacent the mounting device. The hall effect sensor may be in communication with the control circuit. The hood may comprise a transparent face shield and a mounting element configured to removably couple with the mounting device of the helmet. The control circuit may be configured to receive a signal from said hall effect sensor indicating the coupling of said mounting element of said hood with said mounting device of said helmet.

Abstract: Embodiments of the invention include a filtration element. In an embodiment, the invention includes a filtration element for an airplane cabin that includes a first media portion upstream from a second media portion. The first media portion can include activated carbon. The second media portion can include a catalyst material. Other embodiments are also included herein.

Abstract: Unlike the existing powered air-purifying respirators (PAPR) that are bulky, heavy, and expensive the invention offers a light-weighted inexpensive portable PAPR consisted of a single piece secured on user's head. The respirator is for use in contaminated environment including one with highly contagious viruses such as SARS-CoV-2 that causes COVID-19. A clear visor of the respirator protects eyes, nose, and mouth. The rest of the user's head protected with a soft airtight cover. A small fan or fans pump air through the filters. Because the fan capacity exceeds airflow required for breathing, air pressure under the cover is slightly higher than ambient pressure. It protects the visor and user glasses from fogging and prevents leaks through any looseness. A special port allows use of equipment and devices as a stethoscope for medics or oxygen supply for patients.

Abstract: A personal protective device (PPE), which can include a face cover assembly and a bodysuit configured to be worn by a human user. The device protects users against airborne aerosol particles containing viruses or other infectious agents while enabling improved flexibility relative to prior art designs. The device includes a helmet-like” rotating face cover assembly that fits over the user's head and attaches to a collar on the biohazard bodysuit. This rotating face cover assembly has a plurality of different mask sides, each with differing geometries or other properties. The device enables a user to can rotate the cover and select a given mask side that best meets that user's needs. The different mask sides can accommodate different facial geometries, eyewear types, and use cases.

Abstract: An exhaust valve shroud for a personal protection respiratory device, the shroud comprising a main body defining an inlet for receiving exhaled air from an exhalation valve, an outlet for emitting exhaled air from the shroud, and a perimeter flow conduit for carrying the exhaled air from the inlet to the outlet, wherein the perimeter flow conduit includes a bifurcated transition section which receives air from the inlet in a substantially forward facing direction and directs the air into first and second substantially downwardly extending flow passages, each of which passages are in communication with the outlet.

Abstract: A soft medical silicone edged cushion may significantly reduce air leakage and provide comfort to a wearer of a face mask, for example, when the face mask is continually worn by a healthcare worker for a twelve hour shift of medical duty. The cushion may preferably be U-shaped and comprise a cross-section for holding an extra soft silicone gel or air, yet be sufficiently hard and elastic and of predetermined circumference to be adaptable to self-installation to the lateral edges of a face mask and coatable to protect from the escape of air and fit comfortably on a face despite the use of elastic straps with the face mask or the presence of solid plastic lateral edges of an oxygen mask or a ventilator mask. The cushion may be used to cushion a solid plastic laterally edged oxygen or ventilator mask against the use of elastic ties to tie the face mask around a patient's head.

Abstract: An air-filtering protection device includes a filtering mask and an actuating and sensing device. The filtering mask is for being worn to filter air. The actuating and sensing device is mounted and positioned on the filtering mask and includes at least one sensor, at least one actuating device, a microprocessor, a power controller and a data transceiver. The at least one actuating device is disposed on one side of the at least one sensor and includes at least one guiding channel. The actuating device is enabled to transport air to flow toward the sensor through the guiding channel so as to make the air sensed by the sensor.

Abstract: A driving and information transmitting system for an air-filtering protection device includes a filtering mask, an actuating and sensing device mounted on the filtering mask, a power supply device and a connection device. The actuating and sensing device includes at least one sensor, at least one actuating device, a microprocessor, a power controller and a data transceiver. The actuating device is enabled to transfer air to flow toward the sensor. The power supply device transfers an energy to the power controller for enabling the sensor and the actuating device. After monitored information is generated by the sensor and processed into an output data by the microprocessor, the data transceiver receives and transmits the output data to the connection device. After a control command is given by the connection device, the data transceiver receives and transmits the control command to the microprocessor to control the sensor and enable the actuating device.

Abstract: An adapter for connecting a breathing tube to a headpiece includes: a housing including a first portion configured to connect to a breathing tube, a second portion configured to connect to a headpiece, and a hollow cavity extending through the first portion and the second portion to define a flow path for breathable air received from the breathing tube to travel through the adapter for delivery to the headpiece; and a speaker configured to emit an audible sound into the flow path. The speaker is positioned within the housing so that, when the adapter is connected to a breathing tube and a headpiece of a respirator system, the speaker is in close proximity to the headpiece to help ensure sound emitted from the speaker is audible to a user wearing the headpiece. The speaker is also positioned outside of the flow path to prevent air flow obstruction within the adapter.

Abstract: A Twist-interlocking Engine Housing and Air Filter System and Method is disclosed. The filter assembly provides unequaled ease of installation and removal, as well as superior sealing between the housing and the filter assembly. For installation, the user needs only to insert the filter into the housing and then give the filter assembly a one-quarter turn or less to lock the filter assembly into the housing. There are features within the filter base that snap-locks the filter in place to resist inadvertent loosening. Finally, the housing and filter are designed so that the outer flange of the filter base is recessed into the side of the housing in order to prevent the intrusion of unwanted grime and/or fluids.

Abstract: A mouth guard includes a pair of spaced-apart molar receiving members with an inner wall extending therebetween. The inner wall is configured for insertion between a user's lips and teeth. An outer wall is configured to confront an exterior surface of the user's lips. A conduit extends between the inner and outer walls and includes a passage formed therethrough. The passage extends through the inner wall between the molar receiving members and extends through the outer wall whereby a user may breathe or drink through the passage.

Abstract: A powered air respirator kit comprising visor (9) removably attachable to a front edge of a safety helmet (4), a drive unit (1) removably attachable to said safety helmet (4), at least one filter module removably attachable to said safety helmet such that, in use, a fluid flow path is defined through said filter module to a space defined between a user's face and an inner surface of said visor, the kit further comprising a power module (10) removably attachable to said safety helmet and, in use, electrically connectable to said drive unit (1).

Abstract: A surgical helmet assembly including a ventilation system for circulating air around the head of a user. The surgical helmet assembly includes a surgical helmet including a brow bar to be positioned around the head of the user and a chin bar extending from the surgical helmet to be positioned in front of the chin of the user. The chin bar and brow bar include an airflow channel in fluid communication with a fan at the rear of the surgical helmet. The fan generates a flow of air from an airflow inlet at the rear of the surgical helmet through the airflow channel in the chin bar to an airflow outlet in the chin bar and past a user's face in an upward direction and through the airflow channel in the brow bar to an airflow outlet in the brow bar and upward over the user's head.

Abstract: An air delivery hose (10) has a CBRN resistant outer butyl rubber layer (12) convolute over a metal wire reinforced thermoplastic polyurethane inner hose (14). A combination unit respirator (20) has an air delivery hose (10, 10?) with a proximal end (22) with a three position lockable switch (40) that allows selection of APR, PAPR or SCBA modes, and a distal end (24) with a compact demand valve (30) responsive to the switch position. A filter cover accessory (60) is a modular accessory to a PAPR manifold that protects a PAPR filter (62) from premature degradation in harsh environments.

Abstract: A blower filter respirator system (1) has a filter element (3) for filtering ambient air (33), a blower unit (30) and a face part (7) with a tube element (9)—face part/tube combination (79)—for feeding an amount of breathing air (37) to a user (100). A pressure sensor (8) is on an outlet side (35) of the blower unit (30) measuring breathing air pressure values (81) by detecting a pressure difference on the outlet side (35) of the blower unit (30) against the ambient air (33). A control unit (5) is configured to operate the blower unit (30) and control breathing air (37) and is configured to determine a desired pressure value (83) for current operation with the face part/tube combination (79) from operation-related properties (530) of the blower unit (30) and specific properties of the face part/tube combination (79) and for comparing with the current pressure value (81).

Abstract: The present invention relates to oxygen sensors for medical ventilators. A medical ventilator includes a patient circuit delivering inspiratory airflow to a patient and returning expiratory airflow from the patient back to the ventilator. A manifold includes an air flow path into the patient circuit, and a port with an opening for an oxygen sensor. When mated to the port, the oxygen sensor samples the air in the air flow path and detects the amount of oxygen in the air. When the oxygen sensor is inserted into the port, a valve is biased open, to allow airflow through the opening into the oxygen sensor during ventilation. When the oxygen sensor is removed from the port, the valve biases into a closed position covering the opening, to prevent leaks. The ventilator can then continue to operate without the oxygen sensor in place.

Abstract: A method and system according to preferred embodiments of the present invention allows optimizing the dispensing of aerosol medicaments. In particular the system according to a preferred embodiment of the present invention allows the administration of an exogenous pulmonary surfactant to very young patients (e.g. preterm neonates). A catheter 101 conveys atomized surfactant directly to the retro-pharyngeal region in order to increase efficiency of the medicament administration without being invasive: this is particularly important for very young patients, such as pre-term born neonates suffering from neonatal Respiratory Distress Syndrome (nRDS). According to a preferred embodiment of the present invention the catheter is made of biocompatible flexible material (e.g. plastic material). It is possible to couple the catheter with a rigid scaffolding (e.g. metallic) to increase stiffness of the device and to improve easiness of positioning operations.

Abstract: A pulling element is provided for automatically pulling a closing element out of a filter of an escape filter device. An escape filter device is also provided that has a hood and a filter integrated into the hood, with at least one such pulling element. An escape filter device system is also provided having such an escape filter device and a device shell. A method is provided for mounting an escape filter device system.

Abstract: A head-mountable flow generator is configured to deliver a flow of breathable gas at a continuously positive pressure with respect to ambient air pressure to a patient interface in communication with an entrance to a patient's airways including at least an entrance of the patient's nares, while the patient is sleeping, to ameliorate sleep disordered breathing. The flow generator includes a motor, an impeller assembly and housing that encases the motor and the impeller assembly. The housing is configured to be mounted on the patient's head and comprises an inlet to receive the flow of breathable gas and a pair of opposing outlets to deliver the flow of breathable gas. In addition, the impeller assembly is configured to pressurize the flow of breathable gas received from the inlet, and the housing is configured to convey the pressurized flow of breathable gas through both outlets.

Abstract: A mask against atmospheric PM 2.5 includes a mask body and a filter layer located in the mask body. The filter layer includes a carbon nanotube structure. The carbon nanotube structure includes a plurality of carbon nanotube films stacked and crossed with each other. The carbon nanotube structure includes a plurality of micropores. A diameter of the micropores ranges from about 1 micrometer to about 2.5 micrometers.

Abstract: A dispensing assembly for a container filled with a medicinal substance or formulation, the container being suitable for administering the medicinal substance or formulation via inhalation, buccal or sublingual delivery. The dispensing assembly includes a housing (1) defining a patient port through which, in use, the medicinal substance or formulation is dispensed. The dispensing assembly further includes a cap (3) that can be engaged with and disengaged from the patient port to close and open the patient port and an adhesive tape (10) having one portion (12) affixed to the housing and a second portion (11) affixed to the cap, such that when the cap is disengaged from the patient port, the cap is still connected to the housing.

Abstract: A device for filtering air comprising a base, a fan functionally attached to the base, an air filter releasably attached to the base, and a substantially air impermeable outer sleeve is provided.

Abstract: The present invention relates to a composition for generating oxygen, comprising at least one oxygen source selected from chlorates and perchlorates, to an oxygen generator comprising such a composition, and a method for generating oxygen by decomposing such a composition. The present invention further relates to the use of zeolite compounds as multifunctional components in the oxygen generating compositions.

Abstract: An oxygen concentrator an inlet opening configured to receive air. The concentrator also includes a compressor configured to pressurize the air received through the inlet opening. An inlet opening restrictor is configured to dynamically change a characteristic of the inlet opening responsive to increased or decreased demand for the pressurized air. The concentrator further includes a sieve bed configured to separate the pressurized air into a concentrated gas component for delivery to a subject.

Abstract: The invention relates to a system for breath test of a person. It includes a sensor unit configured to sense the presence/concentration of a volatile substance, e.g. alcohol, present in air flowing through a predefined inlet area and generating a signal corresponding to the concentration of said substance. An analyzer determines the concentration of said substance in the breath of said person. It comprises means for the temporary interruption of said air flow at a point in time coinciding with the detection of a breath. It also relates to a method comprising interrupting the flow through said predefined area for a predetermined period of time, and detecting the concentration of said substance during said interruption.

Abstract: A self-contained breathing device for use in fighting fires comprising a hood for covering a wearer's head, a membrane for sealing the hood to create a breathing chamber inside the hood, and a source of oxygen disposed inside the hood. The source of oxygen is connected to the user by a conduit inside of the hood, and another conduit directs user-exhaled carbon dioxide to the source of oxygen. The breathing device includes a visual indicator inside of the hood that reacts to the presence of a gas within the hood and provides visual feedback to the user based on a quantity of the gas present in the hood.

Abstract: In some examples, a system includes an article of personal protective equipment (PPE) having at least one sensor configured to generate a stream of usage data; and an analytical stream processing component comprising: a communication component that receives the stream of usage data; a memory configured to store at least a portion of the stream of usage data and at least one model for detecting a safety event signature, wherein the at least one model is trained based as least in part on a set of usage data generated by one or more other articles of PPE of a same type as the article of PPE; and one or more computer processors configured to: detect the safety event signature in the stream of usage data based on processing the stream of usage data with the model, and generate an output in response to detecting the safety event signature.

Abstract: A full face mask (1) for a PAPR (Powered Air Purifying Respirator) to be used in health hazardous environments, having an air inlet (7, 8) and an air outlet (16), manufactured in one piece from a transparent plastic in a one step vacuum forming process with a single curved field of vision (4) exempt from distorsions and comprising a compartment (5) inside a forehead area of the full face mask for accommodating a blower unit (2).

Abstract: A system and method of use for an accountability system within a pump panel for signaling an alarm condition to first responders. The method and system include a display embedded within a pump panel, and a radio frequency (RF) sub-system. The RF sub-system is configured to receive transmissions from a respiratory protection device (RPD). The RPD is configured to transmit an alarm condition. The method and system also include a controller coupled to the display and the RF sub-system. The controller is configured to instruct the display to display an accountability indicator once the alarm condition is received by the RF sub-system.

Abstract: Provided herein is a positive air pressure facemask, a multi-staged filter system for a positive air pressure facemask, and exemplary methods for replacing the filter system of a positive air pressure facemask while the mask is in continuous use and actively worn by a user. The multi-staged filter system includes a front filter assembly having a plurality of removable filter layers for collecting debris and particulate matter on the exterior of the filter system, a blower assembly, and at least two staged filter inserts contained in the housing of the filter system. The staged filter inserts are easily replaceable and can be changed without requiring the user to remove the facemask or to be exposed to the ambient air.

Abstract: A portable intake air sterilizing apparatus is disclosed, which allows prevention of a worker's infection with virus/bacteria and which can allow, at the same time, the worker to work comfortably. The apparatus includes a cover member C for covering one or both of the nose and the mouth, an air intake portion K for the inner space of the cover member C, and a chlorine dioxide slow-release portion J capable of releasing chlorine dioxide gas into an intake air in association with introduction of this intake air from the air intake portion K.

Abstract: A self-contained breathing device for use in fighting fires comprising a hood for covering a wearer's head, a membrane for sealing the hood to create a breathing chamber inside the hood, and a source of oxygen disposed inside the hood. The source of oxygen is connected to the user by a conduit inside of the hood, and another conduit directs user-exhaled carbon dioxide to the source of oxygen. The breathing device includes a visual indicator inside of the hood that reacts to the presence of a gas within the hood and providing visual feedback to the user based on a quantity of said gas present in the hood.

Abstract: A safety breathing apparatus has a sensor for measuring the difference in pressure between two points in the gas delivered to a head unit. The sensor is used to measure the difference in the pressure of the gas supplied through the apparatus between the two points in the gas flow, and the pressure difference is then used to calculate the gas flow rate.