Abstract: A container for a plurality of molecular sieve beds for use in a pressure swing oxygen concentrator. An extrusion defines at least two and preferably at least three passages extending between open ends of the extrusion. The extrusion ends are closed by first and second end caps secured to the extrusion. Two of the passages form separate molecular sieve containers and a third passage may form an accumulator for storing concentrated oxygen. In a preferred embodiment, the first end cap has separate inlet ports for each molecular sieve container and an outlet port for the accumulator. The second end cap has separate outlet ports for each molecular sieve container and an inlet port for the accumulator.

Abstract: The invention relates to continuous positive airway pressure (CPAP) respiratory therapy apparatus for treatment of apnea, hypopnea and other sleep disorders, and particularly to a control for the CPAP apparatus. A blower is connected through a hose and a mask, such as a nasal mask or a nasal cannula, to the patient's respiratory airway. An air flow sensor and an air pressure sensor are located at the blower end of the hose. Optionally, a vent valve also may be located at the blower end of the hose. The sensor outputs are used to estimate the air pressure at the mask and the air flow sensor output is used to determine the gross air flow to the hose, the patient air flow and the occurrence of patient snoring. The air flow sensor output also is used to generate a square wave breathing signal. The breathing signal may be used by a microprocessor to control the optional vent valve to establish different levels in the applied pressure during inspiration and expiration.

Abstract: The invention relates to continuous positive airway pressure (CPAP) respiratory therapy apparatus for treatment of apnea, hypopnea and other sleep disorders, and particularly to a standby control for automatically operating an air blower in CPAP apparatus. A blower is connected through a hose and a mask, such as a nasal mask or a nasal cannula, to the patient's respiratory airway. Initially, the blower is in a standby mode in which it is either turned off or, preferably, operated at a low speed. When a patient starts breathing through the mask, the blower is automatically switched to an operating mode. In the operating mode, the blower may be controlled to initially supply a low air pressure to the mask which either is increased after a sufficient time delay to allow the patient to fall asleep or is increased in response to the detection of a respiratory event such as apnea or hypopnea.

Abstract: Portable gas dispensing systems of the type in which pulsed doses of a respirating gas such as oxygen are supplied to a patient with breathing difficulties are provided with means to generate electricity from energy extracted from the expanding gas rather than relying solely upon batteries for power to operate the system. A pneumatic motor, which may be integral with the system dose metering means, is powered by expanding gas and drives an electrical generator to produce sufficient electricity to at least supplement that required for system operation allowing for an increase in the service time per fill or a decrease in system weight or both.

Abstract: A gas concentration and/or bulk flow rate sensor suitable for measuring the oxygen concentration and the bulk flow rate of gas delivered to a patient for medical purposes. Two piezoelectric transducers mounted on a printed circuit board are interconnected by an elongated coiled tube. The gas is flowed around one of the transducers, through the tube and around the other transducer. Periodically, one of the transducers is energized with a single short duration pulse to transmit a sonic wave through the gas to the other transducer. The travel time for the sonic wave is measured. The two transducers are alternately used as transmitters and receivers so that the wave travel time is measured both with and against the gas flow direction. A thermistor is located in the center of the coiled tube for measuring the temperature of the gas. From the measured times, the measured temperature and stored formulas, a microprocessor calculates the oxygen concentration and/or the bulk flow rate for the gas.

Abstract: An improved aerosol chamber for an ultrasonic nebulizer which prevents relatively large medicament droplets from being inhaled by a patient. The chamber has a housing formed from a polycarbonate resin and is generally cylindrically shaped with a spherical top surface. The chamber includes an air inlet formed in the top surface and an aerosol outlet formed in a side surface. A centrally located mist tube extends coaxial from the air intake downwardly past the aerosol outlet. A longitudinally extending slot is formed in the mist tube facing the side surface of the housing diametrically opposite the outlet. The slot extends from a lower edge of the tube upwardly toward the air intake. A geyser baffle is disposed at an angle within the mist tube above the slot to deflect larger droplets away from the slot. The baffle includes an upper edge spaced from an adjacent inner surface of the mist tube to define a relatively small gap to allow inlet air to flow through the mist tube.

Abstract: A system for delivering warm humidified air to a patient. Pressurized air is heated to a predetermined temperature and a portion of the heated air is humidifed to substantially 100% relative humidity. The warm humidified air is delivered to a patient through an inner one of a pair of coaxial hoses. The remaining heated air is passed through an annular passage between the two hoses to maintain the temperature and vapor content of the warm humidified air delivered to the patient.