Abstract: The invention presents a method for deriving respiratory data from single lead ECG recordings for monitoring the autonomic nervous system, specifically the parasympathetic and sympathetic nervous systems independently and simultaneously. The ECG derived respiration for ANS monitoring devices generally includes a method for non-invasive monitoring of the respiratory activity for the assessment of the parasympathetic and sympathetic (P&S) branches of the autonomic nervous system. The EDR signal is used to analyze and assess the individual activities of, and interactions between the sympathetic and parasympathetic divisions of the ANS. The present invention applies a QRS peak detection algorithm to ECG signal. The peak amplitudes and respective time locations are then used to generate the respiration signal. The EDR provides an approximate but reliable estimate of the respiratory activity.