A pulse oximetry sensor having a temperature indicator and a method of
operating such a sensor to visually indicate to an operator the
temperature of the sensor and hence a measure of the temperature of the
tissue location to which the sensor is attached. In one embodiment, the
temperature indicator is a color changing liquid crystal temperature
monitor. The liquid crystal temperature monitor includes a number of
segments, each of which is activateable within a predetermined
temperature range to be monitored. In other embodiments of the present
invention, the oximetry sensor includes an active regulated heating
element to enhance blood perfusion within the tissue location being
monitored. In either embodiment, the temperature indicator provides the
operator with an effective way of monitoring the temperature of the
sensor and the adjacent tissue location. In case of a heated sensor, the
temperature indicator informs the operator that the warming function of
the sensor is functioning correctly. In case of a nonheated sensor, the
temperature indicator informs the operator regarding a measure of the
degree of perfusion.