A medium- and high-pressure pulsed jet generator (1) for injecting controlled volumes of at least one medical liquid (7) includes a high-pressure chamber (2) and at least one connector (24) for at least one flexible pouch containing the medical liquid. The flexible pouch/es (6) is/are connected, via a connection tube, to a hydraulic sequencer (28) which is mounted in the high-pressure chamber, is exposed to the pressure inside the chamber (2), sequences the liquid discharged from the flexible pouch into a pulsed jet (11), is composed of a hydraulic connection (20) that is designed as or includes a deformable flexible sleeve (29) hydraulically communicating with the pouch/es (6) at the inlet and with a hand-held intervention element (40) or a catheter at the outlet, and includes hydraulic stops (31, 32) that are disposed on both sides of the flexible deformable sleeve (29) and are operated using a control element (33).