The present invention provides a device for indicating the location of a natural cavity in a body, the device comprising, in a preferred embodiment, a piston and cylinder type syringe for the immediate detection of a natural cavity in a multicellular organism by means of utilising the haptic feedback associated with the loss of resistance technique, whilst also providing a visual indication which forms an integrated part of the syringe, to confirm successful needle placement in the desired intracorporeal cavity. Also a method of detecting and locating the distal tip of a probe such as a needle in the natural cavity is described.
