In an embodiment, an apparatus comprises a needle (e.g., hypodermic needle or trocar) and sensor (e.g., fiber Braggs grating sensor) coupled to a system to determine (e.g., in real time) stress and/or vibrations encountered by the needle. Consequently, various embodiments may (a) help identify nearby vessels, (b) determine whether the needle penetrated a hollow body structure, and (c) accurately guide needles towards a target structure (e.g., vessel). Other embodiments are described herein.