automatic methods to find the delay and to sync the original pleth signals I have computed the heart rate from two pleth signals (from two fingers -both are acquisition-ed from two different devices) heart rate pattern looks similar with some delay in it i could manually see the delay and add those offsets to the original pleth ...Is there any automated method to find the delay and to add those offsets  to the original  pleth signals in Matlab( both the pleth signals are  downsampled to same 10 Hz)
Compute the cross-correlation of the two signals and look at the lag at which the cross-correlation takes its maximum value - this will give you the time offset providing the best alignment of the two signals.