US Patent 8043229 Medical tool for reduced penetration force

A medical device is provided having reduced penetration force. The device includes a body having a central hollow channel and a piezoelectric transducer received within and secured to the body. The piezoelectric transducer has a hollow portion concentric with the central hollow channel. A tubular member is associated with and in communication with the piezoelectric transducer. The tubular member has at least one open end formed concentric with the central hollow channel and the hollow portion of the piezoelectric transducer, wherein the transducer is adapted for vibrating at a frequency to produce an oscillating displacement of the tubular member.