A method and apparatus are provided for locating a target region which is situated in a body of a subject, for example for the delivery of drugs. The system cooperates with a reservoir for receiving an injection fluid, a needle in fluid communication with the reservoir, and a sensor operable to detect a characteristic indicative of the fluid pressure in the needle. A signal generator supplies a success signal to an operator that indicates when the needle is present in the target region. A central controller controls the signal generator in response to signals received from the sensor.
