Gas supply apparatus

A gas supply apparatus comprising:

• a gas supply conduit to supply a gas to a digestive tract inside a subject;
• a pressure sensor which detects a pressure in the digestive tract via the gas supply conduit;
• a solenoid proportional valve which regulate an amount of the gas supplied to the digestive tract via the gas supply conduit;
• and
• a control unit which control operation of the solenoid proportional valve, wherein
• the control unit is configured to operate in:
• a first gas supply mode which is a gas supply mode for endoscopy, in which the control unit controls the solenoid proportional valve base on a detection result of the pressure sensor so that the pressure in the digestive tract becomes a set pressure;
• and
• a second gas supply mode which is a gas supply mode for the control unit being configured to estimate a capacity of the digestive tract based on a pressure in the digestive tract before gas is supplied to inside of the digestive tract and a pressure in the digestive tract after gas is supplied to inside of the digestive tract, and to execute diagnostic testing for functional dyspepsia or irritable bowel syndrome, in which the control unit controls the solenoid proportional valve according to a capacity of the digestive tract to supply a fixed amount of the gas into the digestive tract based on the estimated capacity of the digestive tract, and
• the control unit selectively switches between the first gas supply mode and the second gas supply mode.