Meridian’s DPA/HRV device provides tools for the non-invasive assessment of the cardiovascular system. These tools are focused on the measurement of arterial stiffness, the autonomic function, and autonomic balance. The two branches of the autonomic nervous system are the sympathetic and parasympathetic nervous systems. The System also measures physical and emotional stress level. The core technology of HRV (Heart Rate Variability) and APG (Accelerated Plethmography) has been featured in several thousand published studies. The list of symptoms described in the studies include: Cardiovascular disorder - Peripheral circulation disorder - Chronic Stress HRV is the degree of fluctuation in the length of the interval between heart beats in order to: Predict cardiovascular disease - Analyze the functioning of the ANS (Autonomic Nervous System)  Evaluate stress response APG is the 2nd differential waveform of the pulsation from the finger probe in order to indicate and predict: Peripheral circulation disease Arterial Stiffness - Cardiovascular disease