The present invention may be used to estimate operational characteristics of devices that transmit and receive streams of information in a communication system. This torque represents wasted energy that is lost to the system. A propulsion is driven by the engine and includes a jet pump unit disposed at least partially within the tunnel. % of a filler, such as, aluminum hydroxide, 0 to 40 wt. The probe includes a probe body and a helical or loop structure that supports electrodes or other operative elements against the body tissue.