Biopsy devices are presented comprising: an inner needle comprising a tip for piercing tissue, and a cavity for receiving a tissue portion； an outer sheath moving with respect to the inner needle between a forward position of the sheath in which it totally covers the cavity and a backward position in which the cavity is totally uncovered, the outer sheath comprising a cutting edge at its front end configured to cut the tissue portion into the cavity while moving in a forward direction； and at least one of: a sensing unit mounted on the outer sheath such that the sensing unit is aligned with the cavity when the sheath is in the forward position to thereby sense tissue signals from the tissue portion； or a suction system for applying suction force in the cavity to pull the tissue portion into the cavity while the sheath moves in a backward direction.
