Optical fiber based thermometry system for a hyperthermia laboratory

The development and construction of a thermometry system based on optical fiber sensors is presented. This system is used in a laboratory of experimental hyperthermia to characterize the distribution of temperature on a substitute material of biological tissue (phantom), when it is subjected to controlled electromagnetic or ultrasonic radiations. The experiments are carried out inside an anechoic chamber. The temperature sensors were developed based on plastic optical fibers that work under the principle of evanescent sensors. Its presence in the phantom doesn't disturb the electromagnetic fields. The sensors are positioned inside the phantom by means of a system of automated positioning, controlled in precise form through a personal computer (PC) located inside the chamber. An external PC carries out the automation of the experiments using a control software that also allows to visualize the temperature mapping inside the phantom. The measurement of the temperature is carried out with a precision of /spl plusmn/0.2/spl deg/C in the interval of 35/spl deg/C to 45/spl deg/C. The sensors positioning system has a resolution of 2.5 mm and a load capacity of 3 kg. The control and visualization software presents a friendly interface for the user. According to the tests carried out up to now with this thermometry system, we can conclude that the obtained results are satisfactory.