A method and a device are used for determining a characteristic value for the perfusion of modified, in particular pigmented tissue regions in organs of living beings, for example the skin. The transmitting gateway continues to process and transmit voice packets while also detecting DTMF signals. The device manager automatically detects and adds new devices to the multiprocessor system, and the configuration manager automatically reconfigures which processors run the real-time applications. Based on the allocated data usage information, a gateway facilitating a communication session with the mobile device is provided with a threshold amount of data usage information. When the router at the uppermost stream is reached, a protection module is executed to destroy the attack packets. Each heater element is shaped to define at least one broken annulus, in turn, comprising said at least one arcuate portion.