Optical fiber fluorescent thermometry for electromagnetically induced heating in medicine treatment

Abstract

Heating induced by electromagnetic field, such as radio-frequency (RF) and microwave is often used in medical application. MW or RF heating is used in hypothermia and hyperthermia treatments. Hypothermia is a clinical condition in which the internal body temperature is lowered below 35 C . RF heating (at 13.56 MHz or 27. 13MHz) offers a fast, efficient and non-invasive method. Hyperthermia in cancer treatment involves heating ofmalignant tumors to 42.5-43CC for a extended period in an attempt to obtain remission. MW(at 2450MHz) is potentially a useful method for heating deep localized tumors. A serious problem with this heating modality involves the accuracy ofmonitoring and controlling the tissue temperature in the presence of a strong EM field. Conventional thermal sensors such as thermocouples and thermistors are all based on a metallic active element which cannot function in a strong EM field environment. Optical fiber fluorescent thermometry is a better technique to show this problem. In this paper we quantify the factors determining the performance ofthis method, some practical considerations also be described