A high density, low voltage, and low-power one time programmable memory is based on core cells with a one transistor design. In some examples, cardiac activity that appears benign is quantified and a therapy confirmation threshold is adjusted according to how much apparently benign cardiac activity is seen after an initial identification of a treatable condition. The first routine calculates the scaling factor by subtracting a second digital value from a larger third digital value, which represents a nominal voltage value. The video segments may be rich media video segments. The characteristic of video data is determined based, at least in part, on the subset of blocks in the set of N\xd7T blocks that are associated with the frame.