Implementations disclosed herein provide a monitoring technology. In one implementation, a monitoring system measures whole body biometric levels by analysis of changes in vascular volume caused by pulsatile pressure waves and in tissue volume in response to the pulsatile pressure. The monitoring system includes a monitoring device, which uses a light-based measurement technique to measure biometric levels during different activities and at rest. A light source operatively connected to a light sensor, transmits light, reflectively or transmissively, through tissue. The light sensor detects absorption of the light. Based on wavelength measurements of the detected light, the monitoring device produces a PPG waveform representing characteristic effects of certain physiological parameters. PPG pulse data is selected that satisfies a data integrity condition. Based on analysis of the selected PPG pulse data, the monitoring device computes a biometric. Biometric data results can then be selected that satisfy a result integrity condition.
