Apparatus for monitoring depletion and movement of a medical gas supply

A medical gas supply depletion monitor is adapted to be coupled to a container of pressurised gas for supply to a human or animal patient. The apparatus monitors the supply of gas in the container and comprises a pressure sensor operable to sense the pressure of a pressurised gas in the container and a controller which is in communication with the pressure sensor. The controller receives a sensed pressure value and a subsequent sensed pressure value and from the two pressure values, which change over time, the controller determines and indicates the remaining duration of the gas supply. Thus, the invention warns in advance of the need to change the gas supple which may be, for example, an oxygen bottle. A further invention is also claimed which relates to a motion sensor which is coupled to a pressurised gas supply. The apparatus may communicate data to a remote station where the movement of the gas supply or the reduction in gas pressure or the remaining time may be monitored.