Lightweight powered handpiece for a liposuction device and medical device comprising same

The present invention concerns a powered handpiece for imparting to a cannula of a medical device a reciprocal movement of amplitude (Δχ) along a longitudinal axis (X), the powered handpiece comprising a housing (1) at least partially enclosing, (a) a hollow tube (2) extending along the longitudinal axis (X) between an inlet end (21) and an outlet end (2o), configured for translating back and forth along the longitudinal axis (X) by a distance (ΔΧ) relative to the housing (1), the inlet end (2i) being configured for coaxially coupling the hollow tube (2) to a hollow cannula (10), (b) a ring (3) rigidly coupled to the hollow tube (2) and comprising an opening (3o) defined on a plane (X, Y), having a length, L, measured along a first transverse axis (Y) and a width, W, measured along the longitudinal axis (X), wherein Y l X, (c) a cam (4) mounted on a rotation axle (4r) parallel to a second transverse axis (Z) normal to the plane (X, Y) (i.e., X l Y l Z), offset from a centroid (C) of the cam on the plane (X, Y) by a distance (δP), and set at a fixed position relative to the housing (1), the cam being engaged in the opening (3o), wherein upon rotation about the rotation axle, the cam is configured for rotating within the ring and defining a largest radius of rotation (p) defined on the plane (X, Y), and wherein the largest radius of rotation (ρ) is not more than half the length, L, of the opening (ρ ≤ ½ L) and is larger than the width, W, of the opening, wherein the rotation of the cam (4) engaged in the opening (3o) of the ring (3) drives a reciprocal translation of the hollow tube (2) back and forth along the longitudinal axis (X) by the distance (ΔΧ) relative to the housing (1).