Sensors and monitors for a physiological monitoring system having
capability to indicate an accuracy of an estimated physiological
condition. The sensor senses at least one physiological characteristic of
a patient and is connectable to a monitor that estimates the
physiological condition from signals detected by the sensor. The sensor
includes a detector for detecting the signals from the patient which are
indicative of the physiological characteristic. The sensor is associated
with a memory configured to store data that defines at least one sensor
signal specification boundary for the detected signals. The boundary is
indicative of a quality of the signals and an accuracy of the
physiological characteristic estimated from the signals by the monitor.
The sensor further includes means for providing access to the memory to
allow transmission of the data that defines the at least one sensor
boundary to the monitor.