Determining physiological life signs, with a sensor that is in contact with the surface of a patients skin at point proximate an artery, and measuring arterial blood vessel displacement and/or blood pressure changes. A data stream of measurements of is collected and a set of parameters from the collected data, a number of physiological life signs parameters, is extracted from the data. The physiological life signs that can be extracted include heart rate, breathing rate, systolic blood pressure, and diastolic blood pressure.
