Medical vest for High Frequency Chest Wall Oscillation (HFCWO)system, comprising at least a device (1) comprising a deformable chamber (8)and at least a port (5, 6) in communication with the chamber (8) configured tolet a pressurized fluid flowing alternatively in and out the chamber (8) sothat theinflatable device (1) alternatively passes from an inflated configuration to adeflated configuration, characterized in that the device (1) is configured toessentially expand along one single direction (200) when passing from thedeflated configuration to the inflated configuration.
