Length detection system for biopsy device

A biopsy device for removing at least one tissue sample from a body of a living being, the biopsy device comprising:

• a handle unit;
• and
• a disposable unit releasably attached to the handle unit, the disposable unit including:
• a hollow needle having a distal end portion having a cutting edge, and configured to define a longitudinal path;
• a sample-receiving device having a cavity configured to receive tissue, the sample-receiving device configured to move in the hollow needle along the longitudinal path between an extended position, in which the cavity of the sample-receiving device projects from the distal end portion of the hollow needle, and a retracted position, in which the cavity of the sample-receiving device is positioned proximal to the distal end portion of the hollow needle to facilitate removal of the tissue from the cavity;
• and
• a transport device configured to move the sample-receiving device in the hollow needle between the extended position and the retracted position, wherein the transport device includes:
• a bendable elongate element having a proximal portion and a distal end, the distal end being attached to the sample-receiving device, the bendable elongate element having a toothed surface;
• a rotatable gear engaged with the toothed surface of the bendable elongate element;
• and
• a coiling device configured to coil the proximal portion of the bendable elongate element as the sample-receiving device is moved linearly along the longitudinal path from the extended position to the retracted position by operation of the rotatable gear.