A probe assembly is presented for use in monitoring one or more parameters of a subject. The probe assembly comprises: an acoustic port for transmitting acoustic radiation into a region of interest in the subject, at least one light output port for transmitting incident light towards the region of interest, at least one light input port for receiving light returned from the subject, and a control utility integrated in the probe assembly, said control utility being configured for controlling at least one condition of a monitoring procedure and enabling the monitoring procedure upon detecting that said at least one condition is satisfied.
