The present invention provides a system and method for classifying cardiac beats based on activation-recovery intervals or an ARI-related parameter such as the spatial dispersion of activation, recovery or ARIs. Equipment includes a tread base supporting a moving tread belt upon which a user can run or walk, a motor assembly and motor driver to move the tread belt, a plurality of foot sensors, a tread belt motion sensor, a measurement system to estimate user motion based on foot and tread belt sensor signals, and a motor controller to adjust motor assembly speed based on estimates of user motion. Major components and subassemblies are self-fixturing during the final assembly process, eliminating the need for dedicated tools, fixtures and assembly equipment. Flow control filtering mechanisms and a variable reliability margin may be used to adapt dynamically to the current data traffic conditions. The adjusting device adjusts the toner content on the basis of an output of the layer thickness measuring device. IPDA having a cistrans isomer ratio in the range from 6337 to 6634 can be obtained in any desired cistrans isomer ratio, irrespective of temperature, by reacting IPDA with H2 and NH3 in the presence of a hydrogenation catalyst.