Abstract: An adjustable tracheostoma valve is disclosed. The adjustable tracheostoma valve includes a passageway for connecting the trachea with the surroundings. A valve disk is provided in the passageway. The disk is moveable to allow for inhalation and exhalation through the passageway and is configured to close in response to pressure to direct air to the patient's pharynx, esophagus, sinuses, and mouth for speech following surgical removal of the larynx.

Abstract: There is provided a regulation valve for a life support system for use in an aircraft cabin. The valve may have a gas inlet, an air mask supply outlet connected to the gas inlet, and a pressure vest branch interconnected between the gas inlet and an opening. The valve may further have a decompression valve adapted to inhibit gas flow from the pressure vest branch to the air mask supply outlet if pressure in the aircraft cabin decreases below a predetermined value, a one-way valve adapted to inhibit gas flow from the pressure vest branch to the air mask supply outlet at a predetermined pressure difference between the pressure vest branch and the gas inlet, and a one-way dump valve adapted to direct gas from the pressure vest branch to the environment at the predetermined pressure difference between the pressure vest branch and the gas inlet.

Abstract: A vent valve apparatus (10) for use with a system for supplying breathable gas pressurized above atmospheric pressure to a human or animal. The apparatus (10) includes a gas washout vent (15), a vent valve (18) adapted to progressively restrict the flow area of the washout vent (15), and a pressure sensitive vent valve control means (20,22,23). The control means is adapted to progressively cause the vent valve (18) to restrict the flow area of the gas washout vent (15) in response to increases in the pressure of the gas supply, thereby substantially regulating the volumetric flow of gas and/or CO2 gas through the washout vent (15) over a range of gas supply pressures.

Abstract: An oscillating positive expiratory pressure apparatus having a housing defining a chamber, a chamber inlet, a chamber outlet, a deformable restrictor member positioned in an exhalation flow path between the chamber inlet and the chamber outlet, and an oscillation member disposed within the chamber. The deformable restrictor member and the oscillation member are moveable between an engaged position, where the oscillation member is in contact with the deformable restrictor member and an disengaged position, where the oscillation member is not in contact with the deformable restrictor member. The deformable restrictor member and the oscillation member move from the engaged position to the disengaged position in response to a first exhalation pressure at the chamber inlet, and move from the disengaged position to an engaged position in response to a second exhalation pressure at the chamber inlet.

Abstract: A therapy system adapted to treat a patient's ventilatory instability using a ventilatory therapy, a gas modulation therapy, or both. The algorithm implemented by the therapy system monitors the ventilatory instability, such as Cheyne Stokes Respiration (CSR), mixed apneas, CPAP emergent apneas, and complex sleep disordered breathing (CSDB) and treats the ventilatory instability. The algorithm also determine a reference point with respect to the ventilatory instability. The therapy delivery system initiate the treatment based on the reference point.

Abstract: A method for delivering ventilatory support to a patient is presented. The method includes controlling delivery of a first backup breath by delaying onset of the first backup breath, wherein delaying the onset of the first backup breath is configured to allow selection of an appropriate backup rate. Systems and computer-readable medium that afford functionality of the type defined by this method is also contemplated in conjunction with the present technique.

Abstract: Systems and methods are provided for providing ventilation to a patient. An air source is configured to provide pressurized air to a patient through a patient circuit according to a ventilation pattern. At least one sensor is configured to monitor a corresponding physiologic property of the patient. A ventilator control system is configured to calculate an alveolar ventilation value from the monitored physiologic property of the patient, determine at least an optimal frequency for the ventilation pattern from the calculated alveolar ventilation value, and update the ventilation pattern according to the determined optimal frequency.

Abstract: The auxiliary breathing flow channel apparatus for an oxygen mask for pilots and crew of an airplane includes a flow control device with closed and open positions to regulate flow through an auxiliary channel. A pressure sensor such as an aneroid capsule automatically closes the auxiliary channel upon a decrease in cabin pressure. A handle also allows a user to manually move the flow regulating means to a closed position.

Abstract: A demand valve for gas mixing comprises two or more flow control valves that are connected to separate gas supplies. The demand valve includes a common actuation mechanism, such as a diaphragm arranged to displace levers, each of which, in turn, opens and closes proportionally in a substantially constant ratio a respective flow control valve. Inhalation flow drawn through an outlet causes displacement of the diaphragm and hence opening of the flow control valves. Gas from the separate supplies is therefore mixed in a main chamber to a substantially constant composition, regardless of the flow rate demanded, before being dispensed via the outlet.

Abstract: An oscillating positive expiratory pressure apparatus having a housing defining a chamber, a chamber inlet, a chamber outlet, a deformable restrictor member positioned in an exhalation flow path between the chamber inlet and the chamber outlet, and an oscillation member disposed within the chamber. The deformable restrictor member and the oscillation member are moveable between an engaged position, where the oscillation member is in contact with the deformable restrictor member and an disengaged position, where the oscillation member is not in contact with the deformable restrictor member. The deformable restrictor member and the oscillation member move from the engaged position to the disengaged position in response to a first exhalation pressure at the chamber inlet, and move from the disengaged position to an engaged position in response to a second exhalation pressure at the chamber inlet.

Abstract: A positive oscillatory expiratory air pressure respiratory therapy device which is adapted to receive a nebulizer for administering aerosolized medicant for selective administration during oscillatory positive expiratory pressure (PEP) therapy.

Abstract: Disclosed is a cylindrical, single-component two-stage regulator for controlling a pressure and a flow rate of a gas. The regulator includes a housing for holding the two stages having an ingress adapted for connection to a source of gas at a high input pressure and an egress adapted for supplying gas at a lower output pressure than the high input pressure; a first stage for reducing the pressure of the gas from the high input pressure to a fixed intermediate pressure; and a second stage for reducing the pressure of the gas from the fixed intermediate pressure to the lower output pressure and regulating the flow rate of the gas out of the egress. One application of the present invention is for use in scuba (Self-Contained Under-water Breathing Apparatus) applications, where it replaces the traditional two-component user-adjustable regulator. The regulator may be made out of stainless steel, and is small enough to fit into a user's mouthpiece.

Abstract: Disclosed is a cylindrical, single-component two-stage regulator for controlling a pressure and a flow rate of a gas. The regulator includes a housing for holding the two stages having an ingress adapted for connection to a source of gas at a high input pressure and an egress adapted for supplying gas at a lower output pressure than the high input pressure; a first stage for reducing the pressure of the gas from the high input pressure to a fixed intermediate pressure; and a second stage for reducing the pressure of the gas from the fixed intermediate pressure to the lower output pressure and regulating the flow rate of the gas out of the egress. One application of the present invention is for use in SCUBA (Self-Contained Underwater Breathing Apparatus) applications, where it replaces the traditional two-component user-adjustable regulator. The regulator may be made out of stainless steel, and is small enough to fit into a user's mouthpiece.

Abstract: The auxiliary breathing flow channel apparatus for an oxygen mask for pilots and crew of an airplane includes a flow control device with closed and open positions to regulate flow through an auxiliary channel. A pressure sensor such as an aneroid capsule automatically closes the auxiliary channel upon a decrease in cabin pressure. A handle also allows a user to manually move the flow regulating means to a closed position.

Abstract: A breathing regulator having a non-linear positive pressure spring is provided for use in an air supplied respirator. The regulator includes a housing formed from a regulator body and a cover sub-assembly, a diaphragm assembly, and the non-linear spring. The spring holds the diaphragm assembly closed and resists the force applied by air pressure during exhalation by the user, but collapses once a sufficient amount of force has been applied, thereby permitting the user to exhale freely.

Abstract: An electro mechanically-assisted control system for use in a second-stage regulator. Regulator control assembly (20?), also referred to as all-electronic (AE) assembly (20?), includes an electromechanical actuator (EMA) sub-assembly (22) for controlling airflow through single air supply line (23). EMA sub-assembly (22) includes electronically controllable actuator (ECA) (34), which removably seals EMA orifice (36) in wall (30) of pilot chamber (32). ECA (34) is electrically connected with and controlled by control electronics (38). The control electronics include programmable microprocessor (40), which is electrically connected with charge and discharge electronics (42), both of which are electrically connected with power supply (44). All-electronic (AE) assembly (20?) has only an EMA sub-assembly and no mechanical actuator sub-assembly.

Abstract: A valve assembly and a regulator for use therein are disclosed. The valve assembly includes a valve poppet having a first end having a first face and a second end having a second face. The first face has a surface area smaller than the surface area of the second face. The second end of the valve poppet is received in a sealed chamber and a passage provides fluid communication between the inlet of the regulator and the chamber for allowing gas accumulating in the chamber to act on the second face for urging the valve poppet in the closed position without the use of a spring.

Abstract: An electromechanically-assisted control system for use in a second-stage regulator. Regulator control assembly (20), also referred to as EMA assembly (20), includes a mechanical actuator sub-assembly (21) and an electromechanical actuator (EMA) sub-assembly (22) for controlling airflow through single air supply line (23). EMA sub-assembly (22) includes electronically controllable actuator (ECA) (34), which removably seals EMA orifice (36) in wall (30) of pilot chamber (32). ECA (34) is electrically connected with and controlled by control electronics (38). The control electronics include programmable microprocessor (40), which is electrically connected with charge and discharge electronics (42), both of which are electrically connected with power supply (44). Alternatively, regulator control assembly (20?), also referred to as all-electronic (AE) assembly (20?), has only an EMA sub-assembly and no mechanical actuator sub-assembly.

Abstract: This invention relates to a pressure compensating valve and more particularly, but not exclusively, to a balanced pressure compensating valve, or regulator. The valve includes a chamber (6) for containing fluid, defined by a flexible barrier (2) trapped between first (3) and second (4) surfaces. A fluid inlet provides fluid to the interior of the chamber. A fluid outlet selectively allows fluid to pass out of the chamber. Movement of the first (3) and second (4) surfaces relative to each other causes change in contact between the flexible barrier and the first and second surfaces to selectively open the fluid outlet, in a first position, and occlude it between the flexible barrier and one of the surfaces, in a second position.

Abstract: The demand regulator has a duct communicating a pressurized breathing gas admission with a tube connected to the inside of a breathing mask. Dilution air may be added to the breathing gas. A breathe-out valve opens from the tube to atmosphere. A manual control member has a normal position causing operation without an over pressure above atmosphere and with dilution and an emergency position causing the tube to be fed with pure breathing gas (typically oxygen) at high pressure. Operation with over pressure gas feed is prevented mechanically or pneumatically so long as the mask is being stored.

Abstract: A valve-leaf protective structure for pressure regulator of air tank used in diving mainly includes a valve-leaf seat being provided at a lower center with a retaining hole and at two sides with two raised supports, each of which is provided at an upper inner surface with a rotary shaft hole; and a valve-leaf protective cover located between the two raised supports of the valve-leaf seat, and provided at two upper outer ends with two sideward projected rotary shafts for rotatably mounted in the two rotary holes on the raised supports. A lower side of the protective cover is formed into a tongue having a hook provided at a lowermost end thereof to detachably engage with the retaining hole at the lower center of the valve-leaf seat. Therefore, the protective cover may be pivotally turned about the rotary shafts between the raised supports to close or open the valve-leaf seat.

Abstract: A self contained breathing apparatus (SCBA) served by a source of breathing gas with a mask and a demand regulator connected to the mask. The regulator has a flexible diaphragmatic member having a side exposed to ambient that moves in response to pressure differentials to cause a valve mechanism to introduce breathing gas to the mask. A passage provides breathing gas over said diaphragm exposed to ambient which can be a passage from one side of the diaphragm to the other. A protective cover can overlie the passage which can be displaced upon gas flow through the passage. The method purges ambient contaminants from the diaphragm by providing breathing gas over the diaphragm through an opening of the diaphragm.

Abstract: Here is disclosed a regulator for diving free from any possibility that smooth operation of respective components might be obstructed due to the presence of impurities in the air supplied from an air cylinder. In the regulator, a tubular coupler member coupling a regulator for diving to an air hose extending from an air cylinder is provided with a filter assembly.

Abstract: A surge prevention valve may be used to prevent the formation of an initial surge of high pressure. The valve may be located, for example, between a high pressure gas cylinder and a medical pressure regulator. The valve is provided with first and second valves located within a housing and integrating a pressurization orifice. The initial opening of the valve in an axial direction enables gas to flow through the pressurization orifice at a first flow rate. The full opening of the valve in the axial direction enables the gas to flow through the second valve at a second flow rate, which is much higher than the first flow rate. The controlled pressurization of the gas through the orifice delays the time during which the gas reaches full recompression.

Abstract: An improved manual resuscitation device such as a bag-valve-mask (BVM) device with flow control valve to eliminate the danger of patient distension and aspiration of stomach contents during ventilation. The BVM having the usual patient mask with a gas inlet and flexible patient face sealing edge, flexible manually squeezed bag with a one way intake and output valves in flow communication with a gas source and the mask inlet, and exhaust port for exhausting exhaled gas from the mask when the bag output valve is closed. The flow control valve is interposed between the mask and bag to automatically and variably limit the rate of gas flow from the bag to the mask between a predetermined minimum flow rate and a maximum flow rate. A similar flow control valve can be included in any manual resuscitation device such as a pocket mask or face shield to equal advantage.

Abstract: A valve for controlling gas flow to ventilator or physiotherapy apparatus, has a body having first and second inlet ports and an outlet port. A shutter plate is rotatable with respect to said body and adapted selectively to interconnect said inlet ports to said outlet port. Said shutter plate is operable on rotation in a single sense to connect alternately said first inlet port to said outlet port and said second inlet port to said outlet port.

Abstract: The invention relates to a pressure reducing valve having a piston-like plug, and whose output pressure is automatically controlled relative to ambient pressure, particularly for scuba breathing apparatus regulators. According to the invention, an antifriction member (18) is interposed between the pad (13) which forms the valve seat and cooperates with the tubular plug (8) and the threaded stem (17) for adjusting the axial position of the pad (13), which antifriction member is free to rotate and to slide axially and prevents any direct contact between the pad and the adjustment threaded stem (17), thereby preventing the threaded stem from driving the pad along (13) into rotation. The antifriction member may be a disk (18) made of a relatively hard material with an appropriate surface smoothness, such as stainless steel or tungsten or a plastic material known with the trade name DELRIN, or the like.

Abstract: A surge prevention valve may be used to prevent the formation of an initial surge of high pressure. The valve may be located, for example, between a high pressure oxygen cylinder and a medical pressure regulator. The valve also may be used for other purposes. The surge prevention valve may have a housing with an inlet and an outlet. A seal unit may be used to close the main flow path from the inlet to the outlet, and a bleed passageway may be provided in the seal unit to bypass the main flow path. The valve may have an actuator for opening the bleed passageway and for moving the seal unit to open the main flow path. According to a preferred embodiment of the invention, a manual push-then-turn operation is used to open the valve. The actuator may be used to threadedly move the seal unit toward and away from the valve seat to close and open the main flow path. In addition, a valve rod may be provided for closing the bleed passageway.

Abstract: An improved one-way valve for use in breathing apparatus comprising a valve housing, a one-way valve disposed in the valve housing that is in sealing contact to the valve housing, and a flexible retainer ring. The flexible retainer ring allows the one-way valve to unseat a greater distance within the valve housing thereby allowing an increase in the amount of expiratory gas through an exhaust port of the valve housing and the flexible retainer ring also prevents the deformation and inversion of the one-way valve thereby maintaining the proper flow of both respiratory and expiratory gases.

Abstract: An improved respirator filter assembly includes an integral fit seal check mechanism easily controlled by the user. Upon release, the seal check mechanism permits free airflow through the filter assembly. The seal check mechanism includes an air passageway having a sealing rim and a blocking member which is selectively movable between engaged and disengaged positions relative to the sealing rim. A spring element is disposed to releasably maintain the blocking member in the disengaged position during filter assembly operation, wherein a user may actuate the blocking member against the bias of the spring element to move the blocking member into the engaged position to substantially prevent entry of air into the air passageway during seal checking.

Abstract: A vent valve apparatus (10) for use with a system for supplying breathable gas pressurised above atmospheric pressure to a human or animal. The apparatus (10) includes a gas washout vent (15), a vent valve (18) adapted to progressively restrict the flow area of the washout vent (15), and a pressure sensitive vent valve control means (20,22,23). The control means is adapted to progressively cause the vent valve (18) to restrict the flow area of the gas washout vent (15) in response to increases in the pressure of the gas supply, thereby substantially regulating the volumetric flow of gas and/or CO.sub.2 gas through the washout vent (15) over a range of gas supply pressures.

Abstract: The exhalation valve includes a valve housing with a valve seat having an annular shoulder, and a valve poppet having a face with a corresponding annular groove. A soft flexible diaphragm seal disposed between the face of the valve poppet and the valve seat provides a suspended soft seal, ensuring perpendicularity in the valve seal for improved accuracy of valve operation. An annular permanent magnet and an annular magnetic ring are disposed around and spaced apart from a magnetic body to define an air gap in which an electromagnetic coil is disposed. The electromagnetic coil is connected to a control mechanism by a flexible circuit connector that is sufficiently slack that provides minimal force transverse to the longitudinal axis of the valve.

Abstract: A resuscitation and inhalation device which can be used alternatively in each of two modes. The flow of oxygen or gas is controlled by a control valve, itself controlled by a movable member acted upon by the pressure of oxygen or gas in a chamber after having flowed passed the control valve. On meeting a preset maximum pressure, the valve member moves to close the control valve. The movable valve member is acted upon by a magnetic field which is adjustable, and the magnetic field strength sets the pressure at which the valve member moves. Oxygen or gas is admitted to the control valve by two alternative inlet valves, one for resuscitation with only oxygen or gas flowing through the mask, and one for inhalation, with oxygen or gas and air or a second gas being fed through the mask, allowing ambient air to mix prior to the flow to the patient as a result of inhalation effort by the patient.

Abstract: An improved second stage regulator employs a pneumatically-activated anti-set poppet and inhalation resistance adjustment control knob accessible externally of the regulator. The anti-set poppet utilizes a pressure-activated compression spring to seal the air inlet during exhalation. When the regulator is stored, the relaxed spring permits the seal to withdraw from the sharp edge orifice of the air inlet thereby avoiding seal wear which would otherwise diminish the performance of the regulator. The adjustment control knob permits the diver to modify the required cracking effort by changing the amount of spring compression when the regulator is pressurized.

Abstract: Pressure regulator for the first stage of two-stage aqualungs, comprising a high-pressure gas inlet, a high-pressure chamber communicating with this inlet, an intermediate-pressure chamber and a reducing valve interposed between said high-pressure chamber and said intermediate-pressure chamber. Said intermediate-pressure chamber and optionally also said high-pressure chamber are provided with a plurality of outlets. The high-pressure chamber, the reducing valve and the intermediate-pressure chamber are assembled in a cylindrical body.

Abstract: A mouthpiece for a semi-closed type of breathing apparatus for removing carbon dioxide from breathing air circulating from an inhaling port to an exhaling port in a breathing circuit, comprising a casing, a diaphragm which expands when the inner pressure of a casing is increased through an exhaling operation, exhaling valve member for opening and closing the exhaling port, an urging device for urging the exhaling valve member in such a direction as to close the exhaling port, and a lever having one end linked to the exhaling valve member and the other end linked to the diaphragm, the exhaling valve member being opened through the lever when the inner pressure of the casing is increased through the exhaling operation and the diaphragm expands.

Abstract: A resuscitation and inhalation device which can be used alternatively in each of two modes. The flow of oxygen or gas is controlled by a control valve, itself controlled by a movable member acted upon by the pressure of oxygen or gas in a chamber after having flowed passed the control valve. On meeting a preset maximum pressure, the valve member moves to close the control valve. The movable valve member is acted upon by a magnetic field which is adjustable, and the magnetic field strength sets the pressure at which the valve member moves. Oxygen or gas is admitted to the control valve by two alternative inlet valves, one for resuscitation with only oxygen or gas flowing through the mask, and one for inhalation, with a mixture of oxygen or gas and air or a second gas being fed through the mask.

Abstract: A positive pressure demand regulator having a housing with a connection for delivering breathing gas with an outlet connected to the housing for attachment to a mask. A diaphragm is mounted in the housing and a passage connects the outlet and the diaphragm so that the diaphragm can be in fluidically connected relationship to the outlet. A main valve interconnects the breathing gas connection to the outlet for valving breathing gas to the outlet. A cam is attached to the diaphragm for lifting the diaphragm into an inoperative mode with a detent connected to the cam operated by a cam rod engaging a cam surface to lift the detent into a position for placing the detent in displaced relationship from where the diaphragm is in an operative mode, mounted in the housing on the side of the diaphragm opposite from the outlet.

Abstract: The expansion valve unit, coupled to a lever of a diaphragm by means of a rod unit extending through the internal cavity of the housing, includes heat exchange with the surrounding medium, a rod support at the end of the rod unit opposite the valve unit, being also advantageously associated with a heat exchange unit so as to prevent icing, under the effect of expansion of the breathing gas into the housing, of the mechanical control train of the valve unit, in case of use in a cold surrounding medium.

Abstract: A control device for an air inlet valve to a second stage regulator for an underwater breathing apparatus which allows a diver, while wearing the apparatus, to adjust the amount of suction pressure required to activate the air inlet to his mouthpiece. The device comprises a small cylindrical structure and a micrometer-type adjustment screw threadedly engageable with an interior wall of the structure. The structure fits on the air inlet to the second stage regulator and is fluidly connected thereto in such a way that any air entering the regulator must pass through a channel formed in the shaft of the screw. The manually adjustable, micrometer-type adjustment screw, when turned, resets biasing means on the normally closed air inlet valve, altering the suction pressure which the user must supply to open the valve. In addition, the air inlet for the control device, when it is fitted to the regulator, is disposed at a 90 degree angle to the air inlet for the regulator alone.

Abstract: A second stage scuba regulator is provided which includes inlet for receiving a supply of compressed air and a piston valve in communication with the inlet for causing air flow through the regulator when the piston valve is opened. A lever is provided for opening and closing of the piston valve, and an air volume controller is provided, which is independently operable from the lever for varying the amount of air flow through the regulator when the piston valve is opened by the lever.

Abstract: A built-in regulator cone adjusting tool for a second stage regulator having a housing, an inlet port in the housing, and a cone having a front end and being disposed in the inlet port for reciprocal axial movement, the tool including a tubular body configured for axial rotation in the inlet port of the housing and having a first end and a second end, the second end having at least one tab for releasably engaging the front end of the cone for adjusting the relative position of the cone in the housing.

Abstract: In a gas mask, a flexible nosecup is used to prevent humid air that is exhaled from contacting the eye pieces of the mask. The nosecup is equipped with a one-way valve to allow fresh air into the nosecup. The conventional rigid valve body attached to the nosecup is replaced with a valve body molded integrally with the material of the nosecup and a valving element with a concave disk, having its rim seated on the annular valve seat of the valve body. The concave valving element accommodates any flexing of the valve body without losing the seal.

Abstract: A breathing system regulator for a demand breathing system has adjusting apparatus for adjusting the demand required to open the air inlet valve to permit the user to increase or decrease the tension on the biasing spring urging the valve closed, and to decrease or increase the cushioning effect of a stream of air urging the valve closed. Adjusting apparatus is provided in which an air injector device is adjustably positioned to direct a flow of air between positions for adjusting the pressure at the inlet valve side of the regulator diaphragm to control the amount of breathing effort required of the user to open the air inlet valve.

Abstract: A dust cover is provided with a transverse hook such that when the dust cover is secured in place on the first stage of a scuba regulator, the regulator assembly can be handled and hung by the hook without damage to the regulator or damage or kinking of regulator hoses. Embodiments for both American and European (DIN) configured regulators are enclosed.

Abstract: An expander for compressed gas of the type having a valve 12, 13 delivering an expanded gas at 50 from a high pressure gas 6, 7, and a pilot expander 21 delivering via 41 a gaseous control charge into the compartment 17 of the principal expander. Useful in delivering respiratory gas in underwater diving.

Abstract: The regulator second stage for scuba incorporates a semi-balanced valve mechanism of high flow capacity which operates without significant influence from friction. The compression spring is suspended between two axially opposed pins to avoid friction producing contact with the housing walls. The valve mechanism is suspended between a dynamic seal and a lever assembly to avoid friction producing contact with the housing walls. The valve controlling lever rotates a ball bearing and collar mechanism in which ball bearings cooperate with notches to provide high mechanical advantage with very low friction. The diaphragm and exhaust valve cooperate to provide stable interaction which conserves breathing gas during all orientations of the regulator second stage.

Abstract: A breathing apparatus forms a second stage of an inhalation responsive gas pressure regulator. The inhalation diaphragm is in the form of a cylinder within which an arcuate assembly is positioned, the arcuate assembly opening a valve for permitting the introduction of air from a second stage into the casing during inhalation.

Abstract: A portable respirator system for supplying clean, breathable air to a hood or face mask is disclosed. The system can be carried on a waist belt and includes a housing containing air inlet and outlet plenums, and a battery powered, electric motor operated blower connected between the inlet and outlet plenums. The motor can be manually switched between high and low speed operation to supply high quantities of air upon demand caused by high respiration rate and otherwise supply lower quantities of air sufficient for low respiration rates to extend battery life between rechargings. A differential air pressure sensing switch is responsively connected for actuation when the difference between air pressure in the outlet plenum and the pressure of ambient atmosphere is less than a preselected value.

Abstract: The regulator is suitable for use in a breathing apparatus, particularly for aircraft, whose oxygen source consists of an open loop generator delivering oxygen-rich air under a low and variable overpressure. It comprises a respiratory gas inlet and an outlet for connection to a breathing mask. Communication between the inlet and outlet is controlled by at least two main piloted valves located in parallel flow relation and subjected to the pressure prevailing in a same control chamber. The control chamber is continuously connected to the inlet by a restriction and it is connected to the outlet by a pilot valve controlled by the pressure at the outlet. The restriction is preferably variable responsive to the inlet pressure.