Abstract: Methods and apparatus for monitoring a condition of a breathing gas supply by illuminating optically distinct regions that are visible to a user, and by others in a common group, are provided. The breathing gas supply apparatus includes a sensor, processing circuitry, memory, a power supply, and a flexible light transmissive tube having a distributed light source. The sensor detects a condition of a breathing gas supply and generates an output signal correlated with the detected condition. The memory communicates with the processing circuitry and stores the output signal in memory. The flexible light transmissive tube communicates at a proximal end with the pressure sensor and at a distal end with the power supply. The distributed light source illuminates a plurality of optically distinct regions within the tube, where each illuminated region indicates the detected condition of the breathing gas supply within a predetermined value.