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.

A safety breathing apparatus has a sensor for measuring the difference in pressure between two point 1a, 1b in the gas delivered to a head unit 9. 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.

A respiratory protection mask is disclosed. In one example, the respiratory protection mask comprises an upper portion, a lower portion, and a respiratory filter. The respiratory filter comprises an air outlet, and is arranged in, on and/or at the upper portion such that an inhaled airflow can run substantially straight from the air outlet of the respiratory filter through the upper portion, towards the lower portion and/or to a nose of a mask wearer when the respiratory protection mask is worn by the mask wearer.

A surgical protection system to define a barrier between the user and the external environment. The surgical protection system comprising a helmet assembly, a hood and a transparent face shield. The helmet including a shell, a face frame coupled to the shell, a static tab, a first fastener disposed on the face frame; and a fan mounted to the shell and configured to circulate air about the user. The hood may include a first material defining an opening. The shield may be formed from flexible material and disposed within the opening of the hood. The shield may further include a tab extending from a top portion of the shield and define an opening configured to receive the static tab of the helmet to align the shield to the helmet. The first fastener disposed on the face frame may be configured to facilitate removable attachment of the shield to the helmet.

A respirator comprising: an air supply unit arranged to deliver air at its output; headgear comprising a cradle for interfacing with a user's head, and a face covering from within which the user breathes; a tube to receive air from the air supply unit; and an interface component to receive aft from the tube and to deliver said air within the face covering. Components of the respirator and related methods are also described.

A mask apparatus according to the present disclosure includes a mask body provided with a microphone; a mask body cover coupled to a front surface of the mask body and having a front opening through which sound is output forward; a sealing portion coupled to a rear surface of the mask body and forming a breathing space; and a first speaker fixed to one of the mask body and the mask body cover and outputting a sound input by the microphone; in which a first resonance space in which the first speaker is accommodated is formed between the mask body and the mask body cover to amplify the sound output from the first speaker and output the sound to the front opening.

A filter mask for biological material is provided wherein the filter mask has a fan assist for inhalation.

Multi-function masks are presented including: a mask body forming a chamber, where the mask body includes an inner surface, an outer surface, an edge portion, a first intake portion, a second intake portion, a third intake portion, and an exhaust outlet portion, where the first intake portion passes filtered ambient air, where the second intake portion passes filtered and vaporized air, and where the third intake portion passes any of a fluid or a pressurized gas; a flexible contact portion positioned along the edge portion of the mask body for tightly contacting the mask body to a face when worn; and a filter unit positioned along the outer surface of the mask body for providing filtered ambient air to the first and second intake portions and for filtering exhaust air from the exhaust outlet portion.

A powered air purifying respirator composing 2-channel structure for air support includes: a mask unit that is worn on a face to surround a mouth or nostrils of a user; a generator unit that causes outside air to flow in and supplies the air to the mask unit; and first and second connector units that are formed to provide channels of the air by being connected to the mask unit and the generator unit at both sides of the first and second connectors, where the generator unit includes a fan driving module having first and second air supply holes at both sides of the fan driving module, the first and second air supply holes communicating with end portions of the first and second connector units.

A filter mask for biological material is provided wherein the inlet port faces downwardly.