A device, system and method for accessing internal tissue include a probe (108) disposed on a distal end portion of a medical device and configured to be inserted into a body along a trajectory path. A sensor (102) is mounted on a displacement tracker portion (104) of the medical device which is disposed on a proximal end portion of the device. The sensor is configured to measure a distance parallel to the probe between the displacement tracker portion and a tissue surface such that a position of the probe is determinable relative to the tissue surface upon advance or retraction of the probe along the trajectory path.