A overhead transport service vehicle system includes a carriage frame structured and arranged to carry a user. The conversion adapter apparatus includes a camera body side installation portion to receive a camera body, a lens side installation portion to receive an interchangeable lens, and a first communication contact group provided on the camera body side installation portion and connected to a communication contact group. A specific portion of the flow waveform is identified, and a linear regression of the identified portion of the flow waveform is performed to determine an estimated leak flow in the breathing assistance system. The signals received by a transceiver on each twisted pair are represented in a vector form so that the signals received on each twisted pair, and the cross-talk effect that each signal has on one another, can be performed collectively. When drink or foam overflows and bridges a gap between two metal conductors on the lever, resistance is lowered and electricity flows in the detection circuit. The reflective film is coated on at least a portion of the rough surface.