Generator of medium and high-pressure pulsed jets designed to generate high-pressure liquid pulses of at least one medical liquid (7, 35) contained in a flexible bag (6, 36) placed in a sealed high-pressure enclosure placed under medium or high pressure, having at least one outlet for liquids, the generator comprising: • a sealed high-pressure enclosure, • a device for pressurising the high-pressure enclosure comprising: - a pressurised gas source which supplies the high-pressure enclosure with a pressurised gas in order to increase its internal pressure and - a device for regulating the pressure which regulates the pressure inside the high-pressure enclosure, • at least one connector for connecting at least one flexible bag to a connection conduit, the connector and conduit being disposed inside the high-pressure enclosure, the generator being characterised in that it comprises: • a hydraulic sequencer housed in the high-pressure enclosure and comprising: - at least one inlet through which the at least one conduit connected to the at least one flexible bag arrives and an outlet hydraulically communicating with the exterior of the generator, - a flexible hydraulic connection comprising an upstream tube, a downstream tube and a buffer reserve formed by a flexible deformable envelope located between the upstream tube and the downstream tube, the whole being exposed to the high pressure prevailing in the high-pressure enclosure, - at least one hydraulic shut-off valve (30, 32, 34) in the flexible hydraulic connection, - a means for controlling the at least one hydraulic shut-off valve (30, 31, 32, 34) and • a sealed connection means between the outlet of the sequencer and a connecting conduit to a hand piece or a catheter or an instrument for use. • a sealed high-pressure enclosure, • a device for pressurising the high-pressure enclosure comprising: - a pressurised gas source which supplies the high-pressure enclosure with a pressurised gas in order to increase its internal pressure and - a device for regulating the pressure which regulates the pressure inside the high-pressure enclosure, - a pressurised gas source which supplies the high-pressure enclosure with a pressurised gas in order to increase its internal pressure and - a device for regulating the pressure which regulates the pressure inside the high-pressure enclosure, • at least one connector for connecting at least one flexible bag to a connection conduit, the connector and conduit being disposed inside the high-pressure enclosure, • a hydraulic sequencer housed in the high-pressure enclosure and comprising: - at least one inlet through which the at least one conduit connected to the at least one flexible bag arrives and an outlet hydraulically communicating with the exterior of the generator, - a flexible hydraulic connection comprising an upstream tube, a downstream tube and a buffer reserve formed by a flexible deformable envelope located between the upstream tube and the downstream tube, the whole being exposed to the high pressure prevailing in the high-pressure enclosure, - at least one hydraulic shut-off valve (30, 32, 34) in the flexible hydraulic connection, - a means for controlling the at least one hydraulic shut-off valve (30, 31, 32, 34) and - at least one inlet through which the at least one conduit connected to the at least one flexible bag arrives and an outlet hydraulically communicating with the exterior of the generator, - a flexible hydraulic connection comprising an upstream tube, a downstream tube and a buffer reserve formed by a flexible deformable envelope located between the upstream tube and the downstream tube, the whole being exposed to the high pressure prevailing in the high-pressure enclosure, - at least one hydraulic shut-off valve (30, 32, 34) in the flexible hydraulic connection, - a means for controlling the at least one hydraulic shut-off valve (30, 31, 32, 34) and • a sealed connection means between the outlet of the sequencer and a connecting conduit to a hand piece or a catheter or an instrument for use.