Fluid mixing apparatus with valve operated by pulse width modulation driver(s) via controller sensing oxygen content, useful in hypoxic training apparatus

摘要

A fluid mixing apparatus is provided. The apparatus has a mixing volume (10), a primary inlet (7), secondary inlet (9), and an outlet (19) are provided for the volume. The secondary inlet (9) includes a valve (12) which is adapted to be operated by a driver to pulse width modulate the valve between two flow states to achieve a given flow state through the secondary inlet (9). A controller (17) is adapted to provide a control signal for the driver and to read at least one oxygen content value related to at least one portion of a duty cycle related to that oxygen content.