A catheter or cannula arrangement includes a catheter or cannula and a security unit for monitoring a length of stay of the catheter or cannula in a body. The security unit includes a signaling unit, an activation unit, and a timer unit. The signaling unit emits a first signal. The activation detection unit detects a first event and produces a second signal indicative of the first event detection. The timer unit receives the second signal and starts a time duration measurement in reaction thereto, and produces and transmits to the signaling unit a third signal as soon as the measured time duration is reaches a preset time value. The signaling unit emits the first signal in reaction to receiving the third signal. The first event can be an at least partial extraction of a needle from the catheter or cannula.
