A conductor layer 10 is provided so as to prevent pyroelectric destruction occurring in the steps of manufacturing a surface acoustic wave element 1 on the other surface opposite to an IDT electrode formation surface of a piezoelectric substrate 2. The system employs a self-contained, battery operated, readily portable and easy-to-operate head-mounted magnetic depolarizer to generate a transient or time-varying high-intensity magnetic field into and around the user’s head or neck. The device is configured such that, when it is in situ, a fluid transfer chamber having at least one fluid inlet is defined between the casing member wall and porous conduit. An urgency activity detector module generates an urgency message when the changes in the signal indicate an urgency condition.