Abstract: A system and method for measuring heart rate variability (HRV). The system includes at least one biosensor operable to measure at least one signal from the heart. A bioamplifier is also included, the bioamplifier is in communication with the at least one biosensor. The bioamplifier amplifies the at least one signal into at least one amplified analog signal. A portable device is included, the portable device is in communication with the bioamplifier and operable to digitize the at least one amplified signal into one or more digital signals and measure inter-beat intervals from the one or more digital signals and calculate HRV from the measured inter-beat intervals. A database is also included in communication with the portable device, wherein the measured HRV is indexed in the database by one or more criteria.