(a) SW detection criteria: (1) A negative zero crossing (downzero crossing) and a subsequent positive zero crossing (upzero crossing) separated by 0.25–1.25 sec, (2) A negative peak between the two zero crossings with voltage <−80 μV, (3) A negative-to-positive peak-to-peak amplitude >140 μV, (4) A positive slope >90% of the maximum slope, and (5) A positive zero crossing and a subsequent positive peak separated by maximum 2 sec. Right, display of a SW trajectory as map of delays.
