Abstract: A compressor assembly for a portable oxygen concentrator includes a first compressor chamber having a first connector, a second compressor chamber having a second connector, and a tube having a first end having a first connection interface configured to connect to the first connector and a second end having a second connection interface configured to connect to the second connector. The first connection interface is shaped to maintain the connection between the first connector and the first connection interface in a fixed orientation and the second connection interface is shaped to maintain the connection between the second connector and the second connection interface in a fixed orientation. One or more of the first connector, the second connector, and the tube are compliant.

Abstract: A portable oxygen concentrator designed for medical use where the adsorbent beds, are designed to be replaced by a patient. The concentrator is designed so that the power supply and adsorbent bed mount is one module and the compressor and air filter are part of another module configured to provide a unitary cooling and air supply system. Replacement beds may be installed easily by patients, and all gas seals will function properly after installation.

Abstract: A battery retaining system for a portable oxygen concentrator includes a first rail configured to receive a first slide of a battery, a second rail configured to receive a second slide of the battery, the second rail being spaced apart from the first rail so as to form a channel configured to receive the battery, and a flexible stiffening mechanism configured to impart a biasing force on a surface of the battery when the battery is received within the channel. The flexible stiffening mechanism includes a protrusion projecting from the first rail at least partially towards the second rail and a slit positioned behind the protrusion and configured to facilitate travel of the protrusion fore and aft.

Abstract: A compressor assembly for a portable oxygen concentrator includes a first compressor chamber having a first connector, a second compressor chamber having a second connector, and a tube having a first end having a first connection interface configured to connect to the first connector and a second end having a second connection interface configured to connect to the second connector. The first connection interface is shaped to maintain the connection between the first connector and the first connection interface in a fixed orientation and the second connection interface is shaped to maintain the connection between the second connector and the second connection interface in a fixed orientation. One or more of the first connector, the second connector, and the tube are compliant.

Abstract: A portable oxygen concentrator includes a compressor and a controller. The compressor includes a motor, at least one chamber, and at least one piston operably coupled to the motor and movable within the at least one chamber. In some embodiments, the controller is configured to: determine actual motor speeds for commutations steps of the motor during a first rotational cycle; determine an average motor speed during the first rotational cycle; determine a voltage pattern based at least on a comparison of the average motor speed during the first rotational cycle and the actual motor speeds for the commutation steps of the motor during the first rotational cycle; and cause the voltage pattern to be applied to the motor during a second rotational cycle to reduce differences between applied motor torque and variable torque load imparted by the at least one piston.

Abstract: A method of operating a compressor system includes determining an efficiency of a compressor configured to operate at a plurality of output flow settings, including one or more of measuring, calibrating, calculating, or modeling motor efficiency over a range of supply voltage and pulse width modulation duty cycle combinations, each combination including a supply voltage of a plurality of supply voltages and a pulse width modulation duty cycle of a plurality of pulse width modulation duty cycles. The method further includes selecting a supply voltage and a pulse width modulation duty cycle for use at at least one output flow setting of the plurality of output flow settings based on the determined efficiency of the compressor, generating the selected supply voltage by maintaining, reducing, or increasing a nominal supply voltage, and applying the selected pulse width modulation duty cycle.

Abstract: A portable oxygen concentrator designed for medical use where the adsorbent beds, are designed to be replaced by a patient. The concentrator is designed so that the power supply and adsorbent bed mount is one module and the compressor and air filter are part of another module configured to provide a unitary cooling and air supply system. Replacement beds may be installed easily by patients, and all gas seals will function properly after installation.

Abstract: A portable oxygen concentrator designed for medical use where the adsorbent beds, are designed to be replaced by a patient. The concentrator is designed so that the power supply and adsorbent bed mount is one module and the compressor and air filter are part of another module configured to provide a unitary cooling and air supply system. Replacement beds may be installed easily by patients, and all gas seals will function properly after installation.

Abstract: An adsorber for a gas concentrator includes an adsorbent material having adsorbent particles and a vessel housing the adsorbent material. The vessel includes a vessel wall having a non-circular cross section and at least one stiffening support. A combination of a thickness of the vessel wall and a stiffness of the stiffening support is sufficient to limit deformation of the vessel wall to at least one of less than 0.1 mm and less than 25% of an average diameter of the adsorbent particles under a pressure swing of at least 30 psi within the vessel.

Abstract: A battery retaining system for a portable oxygen concentrator includes a first rail configured to receive a first slide of a battery, a second rail configured to receive a second slide of the battery, the second rail being spaced apart from the first rail so as to form a channel configured to receive the battery, and a flexible stiffening mechanism configured to impart a biasing force on a surface of the battery when the battery is received within the channel. The flexible stiffening mechanism includes a protrusion projecting from the first rail at least partially towards the second rail and a slit positioned behind the protrusion and configured to facilitate travel of the protrusion fore and aft.

Abstract: A method of operating a compressor system includes determining an efficiency of a compressor configured to operate at a plurality of output flow settings, including one or more of measuring, calibrating, calculating, or modeling motor efficiency over a range of supply voltage and pulse width modulation duty cycle combinations, each combination including a supply voltage of a plurality of supply voltages and a pulse width modulation duty cycle of a plurality of pulse width modulation duty cycles. The method further includes selecting a supply voltage and a pulse width modulation duty cycle for use at at least one output flow setting of the plurality of output flow settings based on the determined efficiency of the compressor, generating the selected supply voltage by maintaining, reducing, or increasing a nominal supply voltage, and applying the selected pulse width modulation duty cycle.

Abstract: A compressor assembly for a portable oxygen concentrator includes a first compressor chamber having a first connector, a second compressor chamber having a second connector, and a tube having a first end having a first connection interface configured to connect to the first connector and a second end having a second connection interface configured to connect to the second connector. The first connection interface is shaped to maintain the connection between the first connector and the first connection interface in a fixed orientation and the second connection interface is shaped to maintain the connection between the second connector and the second connection interface in a fixed orientation. One or more of the first connector, the second connector, and the tube are compliant.

Abstract: A portable oxygen concentrator designed for medical use where the adsorbent beds, are designed to be replaced by a patient. The concentrator is designed so that the power supply and adsorbent bed mount is one module and the compressor and air filter are part of another module configured to provide a unitary cooling and air supply system. Replacement beds may be installed easily by patients, and all gas seals will function properly after installation.

Abstract: A portable oxygen concentrator designed for medical use where the adsorbent beds, are designed to be replaced by a patient. The concentrator is designed so that the power supply and adsorbent bed mount is one module and the compressor and air filter are part of another module configured to provide a unitary cooling and air supply system. Replacement beds may be installed easily by patients, and all gas seals will function properly after installation.

Abstract: A personal use oxygen concentrator, including; a controllable user interface including at least one of visual and audio indicators, a power supply, a housing, a controllable product gas output device, a blower, a compressor, a selective adsorption system comprising adsorption beds and gas flow control valves comprising at least one of a PSA, VPSA, or VSA oxygen producing system, a programmable controller configured to control at least one of the blower, compressor, output device, user interface, and selective adsorption system, and an integrated smoke detection system and smoke detector controller, mounted within the housing, configured to be controlled by and provide data to the programmable controller, and the programmable controller may perform predetermined control actions when smoke is detected.

Abstract: A personal use oxygen concentrator, including; a controllable user interface including at least one of visual and audio indicators, a power supply, a housing, a controllable product gas output device, a blower, a compressor, a selective adsorption system comprising adsorption beds and gas flow control valves comprising at least one of a PSA, VPSA, or VSA oxygen producing system, a programmable controller configured to control at least one of the blower, compressor, output device, user interface, and selective adsorption system, and an integrated smoke detection system and smoke detector controller, mounted within the housing, configured to be controlled by and provide data to the programmable controller, and the programmable controller may perform predetermined control actions when smoke is detected.