A subscriber access control system configures a network device connected to cable network to affect the behavior of that device. The main device is provided with a readerwriter that is an interrogator that communicates with the wireless IC device of the accessory device. The invention can be combined with various methods for treating obesity, in particular methods that creates satiety by stretching the wall of the stomach or fills out a volume of the stomach. A flash circuit board charges the main capacitor, and drives the flash emitter by discharging the main capacitor in response to an exposing operation. This results in a power savings. An inlet to a first flowline is at least partially defined by the first packer, and an inlet to a second flowline is defined by the second packer.