Circulation monitoring system

A peripheral arterial flow obstruction detection system for providing a predictive diagnosis correlating to the diagnosis peripheral arterial disease. The system includes a host computer and a sensor used to detect and measure a physiological signal from a subject's finger or toe, such as the measurement of a signal using photoplethysmography using a PPG sensor. Sensor data is processed and filtered before being used to calculate a number of time-domain and frequency-domain calculations corresponding to the signal waveform. The calculations are used in a predictive model using a multi-faceted algorithm to provide a predictive diagnosis that is displayed on an indicator such as a monitor.