A laparoscopic instrument includes an elongated barrel portion which mountably extends between operable parts for engagement with internal structures and organs of a subject patient, which are disposed at a first end of the barrel portion, and an actuating mechanism disposed at a second end of the barrel portion which remains outside the patient and which allows actuation of the instrument by the surgeon, for example by hand manipulation. The operable parts include two jaw parts which collectively define a clamp in which an opening size between the two jaw parts is selectively alterable by operation of the actuating mechanism. The operable parts further include a distance displacement sensor to effect distance measurement when the body part of the patient is received between the jaw parts and the instrument moved there along.