The average amplitude of the samples in a signal sample sequence X in a floating-point format is determined for each frame. In the arrangement a consolidated call data records database receives multiple call data records and analyzes them to determine which, if any, are related to the same call. The lengths and positioning of the first and second control arms of each half frame can be varied to create an expandable frame which conforms to the size and shape of the body vessel in which the filtering device is deployed.