US Patent 7597668 Non-invasive temperature measurement

A thermometric device includes a probe having a membrane configured to be applied to an external surface of a body of a subject and one or more temperature sensors located within the probe in thermal contact with the membrane. A processing unit is configured to receive temperature readings from the one or more temperature sensors, to determine time-dependent parameters of temperature change responsively to the temperature readings, to calculate a local temperature of the body using a function including the time-dependent parameters, and to calculate a core body temperature by correcting for a difference between the core body temperature and the local temperature.