The flow line 10, 12, 30 is provided for reducing axial separation of different density fluids passing through the flow line, such as gas and liquids. A saturation detector is configured to detect saturation of the audio filter and to generate an output when saturation of the filter is detected, such as a switch control signal. The image forming apparatus further includes an auger having at least one sensor for conducting a characteristic measurement on the film. An ultrasonic beacon on the catheter may then be located relative to a therapeutic ultrasonic applicator so that the focus of ultrasonic energy from the applicator can be aligned with the arteriotomy. The lower electrode can include a high density metal situated adjacent to the piezoelectric layer and a high conductivity metal layer underlying the high density metal layer. Power usage is minimized by shutting down transmitters, receivers, serial port drivers, and microprocessors whenever possible, and for extended periods when data is not being transmitted.