A device for measuring a concentration of a component in a target sample includes a flow chamber with a first channel that receives a reference sample having a known concentration of the component. The flow chamber also includes a second channel that receives the target sample having an unknown concentration of the component. A pump operates to pump the reference sample and the target sample at a same volume flow rate through the first and second channels, respectively. A thermal mass flow meter measures a thermal conductivity of the reference sample, a thermal conductivity of the target sample, or both.

An oxygen concentrator includes one or more adsorbent sieve beds operable to remove nitrogen from air to produce concentrated oxygen gas at respective outlets thereof, a product tank fluidly coupled to the respective outlets of the sieve bed(s), a compressor operable to pressurize ambient air, one or more sieve bed flow paths from the compressor to respective inlets of the sieve bed(s), a bypass flow path from the compressor to the product tank that bypasses the sieve bed(s), and a valve unit operable to selectively allow flow of pressurized ambient air from the compressor along the one or more sieve bed flow paths and along the bypass flow path in response to a control signal. The valve unit may be controlled in response to a command issued by a ventilator based on a calculated or estimated total flow of gas and entrained air or % FiO.sub.2 of a patient.

A breathing assistance apparatus includes an inner volumetric member pressurizable from a first pressure to a second pressure and an outer volumetric member surrounding at least a portion of the inner expandable volumetric member. The inner volumetric member pressurizes the outer volumetric member as the inner volumetric member is pressurized from the first pressure to the second pressure. In another embodiment, a breathing assistance apparatus includes exhalation and inhalation chambers with respective biasing members providing for the exhalation chamber to apply a pressure to the inhalation chamber and thereby provide assisted inhalation. Methods for assisting breathing are also provided.

An oxygen concentrator includes one or more adsorbent sieve beds operable to remove nitrogen from air to produce concentrated oxygen gas at respective outlets thereof, a product tank fluidly coupled to the respective outlets of the sieve bed(s), a compressor operable to pressurize ambient air, one or more sieve bed flow paths from the compressor to respective inlets of the sieve bed(s), a bypass flow path from the compressor to the product tank that bypasses the sieve bed(s), and a valve unit operable to selectively allow flow of pressurized ambient air from the compressor along the one or more sieve bed flow paths and along the bypass flow path in response to a control signal. The valve unit may be controlled in response to a command issued by a ventilator based on a calculated or estimated total flow of gas and entrained air or % FiO.sub.2 of a patient.

A respiratory ventilator device is described herein. The respiratory ventilator device includes an inhaled air assembly, an exhaled air assembly, and a control system operatively coupled to the inhaled air assembly and the exhaled air assembly. The inhaled air assembly is coupled to a patient respiratory circuit and configured to channel a volume of inhalation air to the patient's lungs to assist in patient inhalation. The exhaled air assembly is coupled to the patient respiratory circuit and configured to remove air from the patent's lungs to assist in a patient exhalation. The control system is configured to operate the respiratory ventilator system in an inhalation mode and an exhalation mode.

A ventilator system for providing respiratory support in cases of acute respiratory failure or severe trauma is described. The ventilator system comprises a ventilator and a tubing system. The system is characterized in that the ventilator comprises a continuous bleed valve configured to be open to air flow from the blower at all times when the blower is operating during both inspiration and expiration; thereby providing a minimal amount of pressure within a patient's lungs at the end of each exhalation—positive end expiratory pressure (PEEP). In an embodiment of the invention the system comprises a manifold block configured to hold the main operating elements of ventilator.

A respiratory ventilator device is described herein. The respiratory ventilator device includes an inhaled air assembly, an exhaled air assembly, and a control system operatively coupled to the inhaled air assembly and the exhaled air assembly. The inhaled air assembly is coupled to a patient respiratory circuit and configured to channel a volume of inhalation air to the patient's lungs to assist in patient inhalation. The exhaled air assembly is coupled to the patient respiratory circuit and configured to remove air from the patient's lungs to assist in a patient exhalation. The control system is configured to operate the respiratory ventilator system in an inhalation mode and an exhalation mode.

The invention relates to a bearing arrangement designed as a fixed/floating bearing for a rotor of a fan, having a bearing tube, a compression spring, a shaft arranged coaxially with respect to the bearing tube, and two identically formed ball bearings arranged between the bearing tube and the shaft, each ball bearing having an inner ring and an outer ring, wherein multiple different fit zones are formed axially along the bearing tube, wherein, in a first axial fit zone, one of the ball bearings as a fixed bearing is attached by its inner ring on the shaft and its outer ring is fixed with a press fit on a continuous, shoulder-free portion of the bearing tube and, in a second axial fit zone, another of the ball bearings as a floating bearing is attached by its inner ring to the shaft and its outer ring is axially displaceably arranged with a clearance fit on a continuous, shoulder-free portion of the bearing tube, wherein the compression spring is arranged in a third axial fit zone and, exerting a preload against the outer rings of the ball bearings, is positioned axially between the ball bearings and is designed to eliminate bearing play of the floating bearing.

A radial fan (1) is provided with a motor (2) and a fan housing, an outer part (4) and an inner part (5) that form a spiral-like pressure chamber (D). A pressure connector (33) which forms an outlet (44) of the radial fan (1) is arranged on the outer part. The fan housing is equipped with a fan wheel (3) which is arranged on a shaft (7) connected to the motor (2), wherein an annular flow divider (8) which surrounds the fan wheel (3) is arranged adjacently to the fan wheel (3) in a radial direction. The flow divider together with the fan housing forming a diffuser (9), which transitions directly into the pressure chamber (D), about the fan wheel (3).

A portable system for delivery of humidified high flow nasal cannula therapy includes a portable system housing, a respiratory circuit positioned within the housing comprising an ambient air conduit and an oxygen conduit merging downstream into a blended air conduit, an air pump positioned within the housing and connected to an upstream end of the ambient air conduit, configured to transfer ambient air into the ambient air conduit, an oxygen supply connection element connected to an upstream end of the oxygen conduit and configured to connect to an oxygen supply, a humidification chamber connected to a downstream end of the blended air conduit and an upstream end of an air output conduit, and a humidification chamber seating portion connected to the housing and configured to seat the humidification chamber, where the humidification chamber seating portion comprises a sterilization light source.