A wireless power transmission system includes, a transmit antenna which in operation produces a wireless field, an amplifier coupled to the transmit antenna, a load sensing circuit coupled to the amplifier and a controller coupled to the load sensing circuit. A monitoring device has one or more sensors and a unique user ID. The one or more sensors acquire user information selected from of at least one of, a user's activities, behaviors and habit information. The monitoring device includes an ID circuitry. A communication interface receives information about the unique user ID when the load sensing circuit indicates the monitoring device is within the wireless field. The indication is created using at least a change in power consumption.