A nanofiber membrane is formed on a microfiber membrane. This device is characterised by the fact that an authorized person wears an identifying device which automatically allows the inhibition of the alarm system, which has been previously activated by motion detectors, properly concealed inside the premises to protect, enabling thus the continuous protection of the site, while managing a large flow of persons. In one embodiment, the HRV parameter is used to adjust a maximum tracking rate in an atrial tracking pacing mode. The fluid metering valve is fluidly connected to the first compartment at a first valve position and is fluidly connected to the second compartment at a second valve position.