Abstract: A wheelchair suspension comprises a frame, at least one pivot arm, at least one front caster, at least one rear caster, a stabilizing system, and a sensor. The pivot arm is coupled to the frame. The front caster is coupled to the pivot arm. The rear caster is coupled to the frame. The stabilizing system is coupled to the frame and the pivot arm. The sensor is arranged such that tipping of the frame causes actuation of the stabilizing system to at least partially resist further movement of the frame.

Abstract: A wheelchair suspension comprises a frame, at least one pivot arm, at least one front caster, at least one rear caster, a stabilizing system, and a sensor. The pivot arm is coupled to the frame. The front caster is coupled to the pivot arm. The rear caster is coupled to the frame. The stabilizing system is coupled to the frame and the pivot arm. The sensor is arranged such that tipping of the frame causes actuation of the stabilizing system to at least partially resist further movement of the frame.

Abstract: A wheelchair suspension comprises a frame, at least one pivot arm, at least one front caster, at least one rear caster, a stabilizing system, and a sensor. The pivot arm is coupled to the frame. The front caster is coupled to the pivot arm. The rear caster is coupled to the frame. The stabilizing system is coupled to the frame and the pivot arm. The sensor is arranged such that tipping of the frame causes actuation of the stabilizing system to at least partially resist further movement of the frame.

Abstract: A wheelchair suspension comprises a frame, at least one pivot arm, at least one front caster, at least one rear caster, a stabilizing system, and a sensor. The pivot arm is coupled to the frame. The front caster is coupled to the pivot arm. The rear caster is coupled to the frame. The stabilizing system is coupled to the frame and the pivot arm. The sensor is arranged such that tipping of the frame causes actuation of the stabilizing system to at least partially resist further movement of the frame.

Abstract: A wheelchair suspension is provided. The wheelchair suspension includes a frame, a front caster pivot arm, a drive assembly, and a rear caster. The front caster pivot arm is pivotally connected to the frame. The front caster is coupled to a front end of the front caster pivot arm. The drive assembly is pivotally connected to the front caster pivot arm. The drive assembly comprises a drive wheel and a motor that drives the drive wheel. Torquing of the drive wheel by the motor in a forward direction causes the drive assembly to pivot with respect to the front caster pivot arm such that the drive wheel moves forward toward the front caster and a distance between a support surface and the connection between of the drive assembly and the front caster pivot arm increases.

Abstract: A wheelchair suspension comprises a frame, at least one pivot arm, at least one front caster, at least one rear caster, a stabilizing system, and a sensor. The pivot arm is coupled to the frame. The front caster is coupled to the pivot arm. The rear caster is coupled to the frame. The stabilizing system is coupled to the frame and the pivot arm. The sensor is arranged such that tipping of the frame causes actuation of the stabilizing system to at least partially resist further movement of the frame.

Abstract: A pumping device compresses fluid, provides a vacuum, or both compresses fluid and provides a vacuum. A pumping device may be used to force gas through a sieve bed, draw gas out of a sieve bed, or both force gas through a sieve bed and drawing gas out of a sieve bed. A pumping device may be operated at high speed to provide a high fluid flow rate with a small pumping device.

Abstract: A wheelchair suspension comprises a frame, at least one pivot arm, at least one front caster, at least one rear caster, a stabilizing system, and a sensor. The pivot arm is coupled to the frame. The front caster is coupled to the pivot arm. The rear caster is coupled to the frame. The stabilizing system is coupled to the frame and the pivot arm. The sensor is arranged such that tipping of the frame causes actuation of the stabilizing system to at least partially resist further movement of the frame.

Abstract: A wheelchair suspension comprises a frame, at least one pivot arm, at least one front caster, at least one rear caster, a stabilizing system, and a sensor. The pivot arm is coupled to the frame. The front caster is coupled to the pivot arm. The rear caster is coupled to the frame. The stabilizing system is coupled to the frame and the pivot arm. The sensor is arranged such that tipping of the frame causes actuation of the stabilizing system to at least partially resist further movement of the frame.

Abstract: A wheelchair suspension is provided. The wheelchair suspension includes a frame, a front caster pivot arm, a drive assembly, and a rear caster. The front caster pivot arm is pivotally connected to the frame. The front caster is coupled to a front end of the front caster pivot arm. The drive assembly is pivotally connected to the front caster pivot arm. The drive assembly comprises a drive wheel and a motor that drives the drive wheel. Torquing of the drive wheel by the motor in a forward direction causes the drive assembly to pivot with respect to the front caster pivot arm such that the drive wheel moves forward toward the front caster and a distance between a support surface and the connection between of the drive assembly and the front caster pivot arm increases.

Abstract: A wheelchair suspension is provided. The wheelchair suspension includes a frame, a front caster pivot arm, a drive assembly, and a rear caster. The front caster pivot arm is pivotally connected to the frame. The front caster is coupled to a front end of the front caster pivot arm. The drive assembly is pivotally connected to the front caster pivot arm. The drive assembly comprises a drive wheel and a motor that drives the drive wheel. Torquing of the drive wheel by the motor in a forward direction causes the drive assembly to pivot with respect to the front caster pivot arm such that the drive wheel moves forward toward the front caster and a distance between a support surface and the connection between of the drive assembly and the front caster pivot arm increases.

Abstract: A wheelchair suspension comprises a frame, at least one pivot arm, at least one front caster, at least one rear caster, a stabilizing system, and a sensor. The pivot arm is coupled to the frame. The front caster is coupled to the pivot arm. The rear caster is coupled to the frame. The stabilizing system is coupled to the frame and the pivot arm. The sensor is arranged such that tipping of the frame causes actuation of the stabilizing system to at least partially resist further movement of the frame.

Abstract: A wheelchair suspension comprises a frame, at least one pivot arm, at least one front caster, at least one rear caster, a stabilizing system, and a sensor. The pivot arm is coupled to the frame. The front caster is coupled to the pivot arm. The rear caster is coupled to the frame. The stabilizing system is coupled to the frame and the pivot arm. The sensor is arranged such that tipping of the frame causes actuation of the stabilizing system to at least partially resist further movement of the frame.

Abstract: An oxygen concentration and compression system includes an oxygen concentrator, a boost stage, a compressor, and a portable container. The boost stage receives oxygen enriched gas at a first pressure from the oxygen concentrator. The boost stage includes a pressure increasing device that increases the pressure of the oxygen enriched gas from the first pressure to a second, controlled pressure. The compressor receives the oxygen enriched gas at the second, controlled pressure and compresses the oxygen enriched gas to a third pressure in the portable container for later use by a patient. A patient outlet provides oxygen enriched gas from the oxygen concentrator or the boost stage for use by a patient.

Abstract: A wheelchair suspension is provided. The wheelchair suspension includes a frame, a front caster pivot arm, a drive assembly, and a rear caster. The front caster pivot arm is pivotally connected to the frame. The front caster is coupled to a front end of the front caster pivot arm. The drive assembly is pivotally connected to the front caster pivot arm. The drive assembly comprises a drive wheel and a motor that drives the drive wheel. Torquing of the drive wheel by the motor in a forward direction causes the drive assembly to pivot with respect to the front caster pivot arm such that the drive wheel moves forward toward the front caster and a distance between a support surface and the connection between of the drive assembly and the front caster pivot arm increases.

Abstract: A wheelchair suspension is provided. The wheelchair suspension includes a frame, a front caster pivot arm, a drive assembly, and a rear caster. The front caster pivot arm is pivotally connected to the frame. The front caster is coupled to a front end of the front caster pivot arm. The drive assembly is pivotally connected to the front caster pivot arm. The drive assembly comprises a drive wheel and a motor that drives the drive wheel. Torquing of the drive wheel by the motor in a forward direction causes the drive assembly to pivot with respect to the front caster pivot arm such that the drive wheel moves forward toward the front caster and a distance between a support surface and the connection between of the drive assembly and the front caster pivot arm increases.

Abstract: A wheelchair suspension comprises a frame, at least one pivot arm, at least one front caster, at least one rear caster, a stabilizing system, and a sensor. The pivot arm is coupled to the frame. The front caster is coupled to the pivot arm. The rear caster is coupled to the frame. The stabilizing system is coupled to the frame and the pivot arm. The sensor is arranged such that tipping of the frame causes actuation of the stabilizing system to at least partially resist further movement of the frame.

Abstract: A wheelchair suspension comprises a frame, at least one pivot arm, at least one front caster, at least one rear caster, a stabilizing system, and a sensor. The pivot arm is coupled to the frame. The front caster is coupled to the pivot arm. The rear caster is coupled to the frame. The stabilizing system is coupled to the frame and the pivot arm. The sensor is arranged such that movement of the frame relative to the rear castor causes actuation of the stabilizing system to at least partially resist further movement of the frame.

Abstract: A pumping device compresses fluid, provides a vacuum, or both compresses fluid and provides a vacuum. A pumping device may be used to force gas through a sieve bed, draw gas out of a sieve bed, or both force gas through a sieve bed and drawing gas out of a sieve bed. A pumping device may be operated at high speed to provide a high fluid flow rate with a small pumping device.

Abstract: A wheelchair suspension comprises a frame, at least one pivot arm, at least one front caster, at least one rear caster, a stabilizing system, and a sensor. The pivot arm is coupled to the frame. The front caster is coupled to the pivot arm. The rear caster is coupled to the frame. The stabilizing system is coupled to the frame and the pivot arm. The sensor is arranged such that tipping of the frame causes actuation of the stabilizing system to at least partially resist further movement of the frame.