The invention relates to a device for the self-locking bidirectional drive of a medical treatment device (18) with a first locking unit for blocking the rotation of an inner part (72) in a first direction of rotation (R1) and for releasing the rotation of the inner part (72) in a second direction of rotation (R2) and comprising a second locking unit for blocking the rotation of the inner part (72) in a second direction of rotation (R2) and for releasing the rotation of the inner part (72) in a first direction of rotation (R1). The inner part (72) is connected to the medical treatment device (18) via a driven shaft (55). Two release elements (122a to 122c, 123a to 123c) are provided which are movable by means of a drive element (36) into one release position each, which release elements prevent the blocking of the rotation of the inner part (72) in one direction of rotation (R1, R2) each so that a rotation of the inner part (72) and of the medical treatment device (18) connected to the inner part (72) via the driven shaft (55) is only possible by means of the drive element (36).
