A biomedical sensor has conducting elements disposed at least partly over a skin-facing surface. A sensing element detects a signal representative of a physiological parameter of a body using the conducting elements. A storage device stores a physiological model. A processor determines sensor placement quality by comparing the signal to the model and operates an indicator to indicate the determined quality. A method of measuring using the sensor includes computing a measurement acceptance criterion using numerous measurements, determining whether a subsequent test measurement corresponds to the measurement acceptance criterion obtained from the computing step, and indicating the results via the indicator. A system for measuring a physiological property of the body includes the sensor, a user interface device to receive measurements from the sensor, and a processor associated with the user interface device and configured to provide feedback if the measurement does not meet a selected acceptance criterion.
