A fuel cell system comprising a fuel cell having plural membrane-electrode assemblies and plates, fuel and oxidant humidifiers and heater exchanger. One method involves determining a brightness value of at least one pixel of each bi-directionally predicted intermediate frame in the sequence as an equal average of brightness values of pixels in non-bidirectionally predicted frames bracketing the sequence of bi-directionally predicted intermediate frames. For each row in the array, a row select line connecting to all of the processing elements in the row. A problematic database object is identified using the performance data for the plurality of database objects, wherein the problematic database object is related to the performance problem. A thermoacoustic imaging system sized to be held within the human hand is also disclosed.